{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:36:07Z","timestamp":1787027767257,"version":"build-2736575974"},"reference-count":59,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2024,7,27]],"date-time":"2024-07-27T00:00:00Z","timestamp":1722038400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cancers"],"abstract":"<jats:p>Breast cancer is a significant global issue, ranking as the second most common cancer among women worldwide and a leading cause of cancer-related deaths. Although the exact causes of this increase remain unclear, factors such as genetics, epigenetics, obesity, sedentary lifestyle, tobacco use, and vitamin D deficiency have been implicated. The Toll-like receptor 9 (TLR9) is recognized for its role in inflammation and innate immunity; however, its specific involvement in breast cancer pathogenesis requires further investigation. This study aims to systematically review the existing literature on TLR9 expression in normal and cancerous breast tissue, providing current knowledge and identifying gaps. Relevant articles in English were from PubMed, Scopus, and Google Scholar, with the inclusion criteria focusing on studies evaluating TLR9 mRNA and protein expression. The review found that TLR9 mRNA and protein exhibit variable expressions in both normal and cancerous breast tissue, highlighting the need for further research to clarify TLR9\u2019s role in breast cancer.<\/jats:p>","DOI":"10.3390\/cancers16152679","type":"journal-article","created":{"date-parts":[[2024,7,29]],"date-time":"2024-07-29T09:50:05Z","timestamp":1722246605000},"page":"2679","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Understanding the Role of Toll-Like Receptors 9 in Breast Cancer"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2984-076X","authenticated-orcid":false,"given":"Umaima","family":"Al-alem","sequence":"first","affiliation":[{"name":"Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, IL 60607, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alaa","family":"Al-Saruri","sequence":"additional","affiliation":[{"name":"Department Psychologie, Friedrich-Alexander-Universit\u00e4t Erlangen-N\u00fcrnberg, 91058 Erlangen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8260-6393","authenticated-orcid":false,"given":"Hasan","family":"Bamahros","sequence":"additional","affiliation":[{"name":"College of Business Administration, University of Hail, Hail 55471, Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0295-6706","authenticated-orcid":false,"given":"Abeer M.","family":"Mahmoud","sequence":"additional","affiliation":[{"name":"Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, College of Medicine, University of Illinois Chicago, Chicago, IL 60612, USA"},{"name":"Department of Kinesiology and Nutrition, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Emily","family":"Sible","sequence":"additional","affiliation":[{"name":"Centre International de Recherche en Infectiologie, CIRI, Inserm, U1111, 69007 Lyon, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Uzma A.","family":"Hasan","sequence":"additional","affiliation":[{"name":"Centre International de Recherche en Infectiologie, CIRI, Inserm, U1111, 69007 Lyon, France"},{"name":"Cancer Research Centre of Lyon, CRCL, INSERM U1052-CNRS UMR5286, 69008 Lyon, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,7,27]]},"reference":[{"key":"ref_1","unstructured":"Ferlay, J., Ervik, M., Lam, F., Laversanne, M., Colombet, M., Mery, L., Pi\u00f1eros, M., Znaor, A., Soerjomataram, I., and Bray, F. 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