TET1 and neoplasm: In addition to PD-1/PD-L1 expression and tumor mutational burden (TMB), several methylation regulators, such as ubiquitin-like with plant homeodomain (PHD) and ring finger domains 1 (UHRF1) and Ten-eleven translocation 1 (TET1), have been reported to be potential biomarkers for ICIs therapy (13, 14).