CD274 and breast cancer: Our results showed that PD-L1 rs4143815 (G/C) variant significantly reduced the risk of BC in homozygous (OR=0.52, 95%CI=0.28-0.96, P=0.049, GG vs CC), recessive (OR=0.44, 95%CI=0.26-0.77, P=0.006, GG vs CG+CC) genetic models.