CTLA4 and breast carcinoma: The ecm-myCAF subset in breast cancer not only increased the proportion of the transcription factor forkhead box protein p3 (Foxp3) + T cells in the CD4+CD25+population, but also upregulated the expression of PD-1 and cytotoxic T lymphocyte associate protein-4(CTLA-4) on their surface, which in turn increased the proportion of TGF-β-myCAF [19].