CDKN1B and hepatocellular carcinoma: To confirm whether Ser10 phosphorylation status of P27Kip1 was associated with CACYBP function in HCC cells, we constructed two P27Kip1 phosphomimetic mutants S10A and S10D, which preferentially adopt nuclear and cytoplasmic localization respectively 34, and reconstituted them in CACYBP-depleted cells.