MEK inhibition induced intratumoral T‐cell accumulation and major histocompatibility complex (MHC) class I upregulation in mouse models, and synergized with immune checkpoint inhibition to promote durable tumor regression. A preliminary clinical trial assessing the combination of a MEK inhibitor with anti‐PDL1 agent showed early signs of efficacy in patients with MSS non‐hypermutated CRC. Here, CD274 is linked to neoplasm.