CTLA4 and neoplasm: Recently, many E3 ligases have been found to target immune checkpoint proteins such as PD1, PD‐L1 and CTLA‐4 to disrupt the immune escape of tumor cells.[22, 23, 24] Moreover, researchers have shown that some E3 ligases can inhibit the activities immune cells and promote tumor growth.[7, 25] However, few studies have directly investigated the family of E3 ligases and their influence on the TME.