Dual effect of vitamin D₃ on breast cancer-associated fibroblasts.

"Declarations Ethics approvals and consent to participateEthics approval: Study protocols were approved by the Bioethical Committee at the Medical University of Wrocław, Poland (approval numbers: 603/2018 and 855/2019).Patient consent: All patients included in the manuscript agreed to take part in the study. Informed consent was obtained from all the participants in this study. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This research was funded by the Polish National Science Center, grant number 2017/27/B/NZ5/01167. The funders had no role in the design of study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results."