In addition, Casitas B-cell lymphoma (c-Cbl) and Casitas B-lineage lymphoma proto-oncogene-b (Cbl-b) are monomeric RING E3 ligases that negatively regulate PD-L1 expression through inactivating STAT, AKT and ERK signaling in lung cancer [29]. The gene discussed is CBLB; the disease is lung cancer.