CD274 and cancer: Overall response rates of 19% with pembrolizumab monotherapy and MPDL3280A (atezolizumab) monotherapy have been reported in advanced TNBCs that express PD-L1 (PD-L1+), with durable responses observed.9,10 Although responses to PD-1 and PD-L1 blockers are not restricted to tumors that express PD-L1, higher response rates have been observed in cancers with PD-L1 expression.11–13