CD4 and breast carcinoma: For example, CAFs in breast cancer may attract CD4+ CD25+ T cells by secretion of C-X-C motif chemokine ligand 12 (CXCL12) and promote CD4+ T-cell differentiation into FOXP3-positive Treg cells or contribute to immunosuppressive M2-like TAM induction in breast cancer and oral squamous cell carcinoma [22].