Kieffer et al further defined specific subsets of FAP+ myCAFs in primary breast cancer responsible for immune suppression through association with enhanced FoxP3+ PD1+ Treg cells; importantly, in vitro coculture experiments with T‐cells indicate that CAFs must adopt a myCAF phenotype to induce FoxP3, PD1 and CTLA‐4 expression [48, 54]. This evidence concerns the gene FOXP3 and breast cancer.