PTEN and hepatocellular carcinoma: Given that PTEN protein can be acetylated by PCAF, this mechanism can also contribute to the occurrence of HCC.90 The tumour suppressor activity of PTEN principally exerts its antagonistic effects on the antiapoptotic, proliferative, and hypertrophic activity of PI3K.125 In cancer biology, PTEN is frequently mutated or deleted in a wide variety of tumours.