CD274 and breast cancer: A similar study by Acs et al. (2017) assessed PD-1, PD-L1, and CTLA-4 expression in PABC and non-PABC women; the expression of PD-1, PD-L1 was seen in peritumoral lymphocytes, however there was no expression of CTLA-4 and elevated PD-L1 expression was associated with early-onset of breast cancer and poor prognosis (89).