PD-L1 knock-out by CRISPR/Cas9 has proven effective in making triple negative breast cancer cells susceptible to chemotherapy through a reduced activation of p38 MAPK signalling pathway, that is dependent on the association of DNA-PKcs and B7-H1 followed by a downregulation of Bcl-2 [74]. Here, CD274 is linked to triple-negative breast carcinoma.