An increasing number of E3 ligases are being identified as the crucial regulators of tumor immune responses, including the membrane-associated RING-CH (MARCH) family of E3 ligases [5] and F-box only protein 38 (FBXO38), which mediate the proteasomal degradation of programmed cell death protein 1 (PD-1) [20,21]. The gene discussed is PDCD1; the disease is neoplasm.