In ER-positive breast cancer cells, CD145- cells were found to reduce the expression of ER, as well as lessened the sensitivity of tumor cells to tamoxifen whereas CD145+ cells displayed opposite effects indicating that the composition of CAF-subsets in TME plays a key role in regulating the therapeutic response to endocrine therapy in estrogen-positive breast cancer patients (41). This evidence concerns the gene ESR1 and neoplasm.