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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">JMIR</journal-id>
      <journal-id journal-id-type="nlm-ta">J Med Internet Res</journal-id>
      <journal-title>Journal of Medical Internet Research</journal-title>
      <issn pub-type="epub">1438-8871</issn>
      <publisher>
        <publisher-name>JMIR Publications</publisher-name>
        <publisher-loc>Toronto, Canada</publisher-loc>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="publisher-id">v27i1e79772</article-id>
      <article-id pub-id-type="pmid"/>
      <article-id pub-id-type="doi">10.2196/79772</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Letter to the Editor</subject>
        </subj-group>
        <subj-group subj-group-type="article-type">
          <subject>Letter to the Editor</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Authors’ Reply: Foundation Models for Generative AI in Time-Series Forecasting</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="editor">
          <name>
            <surname>Leung</surname>
            <given-names>Tiffany</given-names>
          </name>
        </contrib>
        
      </contrib-group>
      <contrib-group>
        <contrib id="contrib1" contrib-type="author">
          <name name-style="western">
            <surname>He</surname>
            <given-names>Rosemary</given-names>
          </name>
          <degrees>PhD</degrees>
          <xref rid="aff1" ref-type="aff">1</xref>
          <xref rid="aff2" ref-type="aff">2</xref>
          <ext-link ext-link-type="orcid">https://orcid.org/0000-0001-8307-3958</ext-link>
        </contrib>
        <contrib id="contrib2" contrib-type="author" corresp="yes">
          <name name-style="western">
            <surname>Chiang</surname>
            <given-names>Jeffrey</given-names>
          </name>
          <degrees>PhD</degrees>
          <xref rid="aff2" ref-type="aff">2</xref>
          <xref rid="aff3" ref-type="aff">3</xref>
          <address>
            <institution>Department of Neurosurgery</institution>
            <institution>David Geffen School of Medicine</institution>
            <institution>University of California, Los Angeles</institution>
            <addr-line>300 Stein Plaza, Suite 560</addr-line>
            <addr-line>Los Angeles, CA, 90095</addr-line>
            <country>United States</country>
            <phone>1 310 825 5111</phone>
            <email>njchiang@g.ucla.edu</email>
          </address>
          <ext-link ext-link-type="orcid">https://orcid.org/0000-0002-6843-1355</ext-link>
        </contrib>
      </contrib-group>
      <aff id="aff1">
        <label>1</label>
        <institution>Department of Computer Science</institution>
        <institution>University of California, Los Angeles</institution>
        <addr-line>Los Angeles, CA</addr-line>
        <country>United States</country>
      </aff>
      <aff id="aff2">
        <label>2</label>
        <institution>Department of Computational Medicine</institution>
        <institution>University of California, Los Angeles</institution>
        <addr-line>Los Angeles, CA</addr-line>
        <country>United States</country>
      </aff>
      <aff id="aff3">
        <label>3</label>
        <institution>Department of Neurosurgery</institution>
        <institution>David Geffen School of Medicine</institution>
        <institution>University of California, Los Angeles</institution>
        <addr-line>Los Angeles, CA</addr-line>
        <country>United States</country>
      </aff>
      <author-notes>
        <corresp>Corresponding Author: Jeffrey Chiang <email>njchiang@g.ucla.edu</email></corresp>
      </author-notes>
      <pub-date pub-type="collection">
        <year>2025</year>
      </pub-date>
      <pub-date pub-type="epub">
        <day>25</day>
        <month>7</month>
        <year>2025</year>
      </pub-date>
      <volume>27</volume>
      <elocation-id>e79772</elocation-id>
      <history>
        <date date-type="received">
          <day>27</day>
          <month>6</month>
          <year>2025</year>
        </date>
        <date date-type="accepted">
          <day>14</day>
          <month>7</month>
          <year>2025</year>
        </date>
      </history>
      <copyright-statement>©Rosemary He, Jeffrey Chiang. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 25.07.2025.</copyright-statement>
      <copyright-year>2025</copyright-year>
      <license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by/4.0/">
        <p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research (ISSN 1438-8871), is properly cited. The complete bibliographic information, a link to the original publication on https://www.jmir.org/, as well as this copyright and license information must be included.</p>
      </license>
      <self-uri xlink:href="https://www.jmir.org/2025/1/e79772" xlink:type="simple"/>
      <related-article related-article-type="commentary-article" id="v27i1e76964" ext-link-type="doi" xlink:href="10.2196/76964" vol="27" page="e76964" xlink:type="simple">https://www.jmir.org/2025/1/e76964/</related-article>
      <related-article related-article-type="commentary-article" id="v27i1e59792" ext-link-type="doi" xlink:href="10.2196/59792" vol="27" page="e59792" xlink:type="simple">https://www.jmir.org/2025/1/e59792/</related-article>
      <related-article related-article-type="correction-forward" xlink:title="See correction statement in:" xlink:href="http://www.jmir.org/2025/1/e79605/" vol="27" page="e79605"> </related-article>
      <kwd-group>
        <kwd>generative artificial intelligence</kwd>
        <kwd>artificial intelligence</kwd>
        <kwd>time series</kwd>
        <kwd>electronic health records</kwd>
        <kwd>electronic medical records</kwd>
        <kwd>systematic reviews</kwd>
        <kwd>disease trajectory</kwd>
        <kwd>machine learning</kwd>
        <kwd>algorithms</kwd>
        <kwd>forecasting</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <p>We thank the authors for their thoughtful letter [<xref ref-type="bibr" rid="ref1">1</xref>] regarding our article “Generative AI Models in Time-Varying Biomedical Data: Scoping Review” [<xref ref-type="bibr" rid="ref2">2</xref>]. We appreciate their careful reading and constructive feedback, which provides us with an opportunity to clarify important aspects of our work and address areas where our presentation may have been unclear.</p>
    <p>We acknowledge the authors’ concern regarding our definition of foundation models (FMs). Their observation is well-taken, and we recognize that our use of terminology was imprecise in certain instances. We appreciate this opportunity to provide clarification. In our work, we intended to refer to FMs as models that have been trained on extremely large and typically unlabeled datasets, encompassing both models that are inherently capable of generative tasks and models that can be adapted for generative forecasting tasks (eg, clinical language models). This broader conceptualization reflects the evolving landscape of how these models are being applied in biomedical time-series analysis, where the distinction between inherently generative models and models adapted for generative purposes is becoming increasingly nuanced. However, the authors raise an important point about the distinction between masked language models and truly generative artificial intelligence (AI) models. We acknowledge that models like GatorTron are indeed masked language models rather than generative AI models in the strictest sense and appreciate the reference to GatorTronGPT as an example of a true generative variant.</p>
    <p>The authors identified an important error in our presentation in Figure 3; we incorrectly labeled certain models as “foundation models” when they should have been categorized as “generative models.” While TimeGPT and denoising diffusion probabilistic models at large scale are FMs, the rest are generative models to be distinguished from FMs. We have corrected this label to avoid further confusion [<xref ref-type="bibr" rid="ref3">3</xref>].</p>
    <p>The field of generative AI applications to biomedical time-series data is rich and ever-growing, and the manuscript intends to offer multiple methodological options for researchers and practitioners. We thank the authors again for their careful attention to our work and their constructive feedback, which ultimately serves to strengthen the scientific discourse in this important area.</p>
  </body>
  <back>
    <app-group/>
    <glossary>
      <title>Abbreviations</title>
      <def-list>
        <def-item>
          <term id="abb1">AI</term>
          <def>
            <p>artificial intelligence</p>
          </def>
        </def-item>
        <def-item>
          <term id="abb2">FM</term>
          <def>
            <p>foundation model</p>
          </def>
        </def-item>
      </def-list>
    </glossary>
    <fn-group>
      <fn fn-type="conflict">
        <p>None declared.</p>
      </fn>
    </fn-group>
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          </comment>
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</article>
