CD274 and neoplasm: Previous reports have shown that MAPK signaling pathway plays an important role in TCR signaling cascade42 and co-inhibition of MEK and PD-1/PD-L1 interaction is synergistic and resulted in a durable tumor regression.43 Therefore, its downregulation of MAPK signaling pathway might also attribute the superior efficacy in the patients with DSPP mutation, and the detailed mechanisms warrant investigation in the future.