CKLF and neoplasm: Studies have found that chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing proteins 6 and 4 (CMTM6 and CMTM4) increase the stability of PD-L1 through downregulating ubiquitination-dependent degradation and lysosome-dependent proteolysis, thus enhancing the ability of tumor cells to suppress immune responses, and providing a new target for combinatorial immunotherapy37,124,125.