We simultaneously ectopically expressed Myc-tagged SAMD4B, Flag-tagged APOA2 and HA-tagged immune checkpoints that are mainly expressed in tumours (PD-L1, PD-L2, FGL1 or HMGB1) and demonstrated that overexpression of SAMD4B could reduce the protein level of APOA2. The gene discussed is PDCD1LG2; the disease is neoplasm.