CD274 and cancer: Recently, two research groups have independently identified the chemokine-like factor-like MARVEL transmembrane domain-containing protein 6 (CMTM6) as a crucial regulator of PD-L1 in a broad range of cancer cells; they found that CMTM6 promotes PD-L1 stabilization in the plasma membrane by inhibiting the ubiquitination of PD-L1, which prevents its subsequent degradation via lysosomes [36,37].