Recently, it has been reported that MDSCs can convert normal B cells into a unique population of programmed death receptor-1 negative, programmed death ligand-1 positive (PD-1- PD-L1+) regulatory B cells (PD-1- PD-L1+ Breg) in breast cancer and that this population has a stronger suppressive effect on T cell immune responses [59]. Here, CD274 is linked to breast carcinoma.