CTLA4 and breast cancer: In the current study, we analyzed the intrinsic mRNA expression of several immunoregulatory genes, such as CTLA-4, PDCD1 (PD1), CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3), JAK2 and FoXO1 in six BC cell lines, their derived mammospheres, and in co-cultures with PBMCs.