PCNA and hepatocellular carcinoma: Recently, a novel immunodiagnostic assay was developed to screen tumor-associated antigens (TAAs) associated with HCC, that includes RGS20 in a panel of eleven TAAs (AAGAB, C17orf75, CDC37L1, DUSP6, EID3, PDIA2, RGS20, PCNA, TAF7L, TBC1D13, and ZIC2) [38].