CD274 and cancer: Colorectal cancer (CRC) is the third most common cancer type in the United States and is often refractory to PD-(L)1 blockade and other immunotherapies, with only tumors harboring a defective mismatch repair system (~15% of all cases) manifesting favorable responses to anti-PD-(L)1 (14, 15).The aforementioned tumors are typically hypermutated, enriched for microsatellite instability (MSI), and display extensive T cell infiltration, while the remaining microsatellite stable (MSS) CRC tumors are often depleted of T cells (16, 17).