PTEN and neoplasm: The PTEN gene codes for phosphatidylinositol‐3,4,5‐triphosphate 3‐phosphatase (PTEN), an enzyme that regulates the PI3K/AKT signalling pathway, a central pathway controlling cellular proliferation, metabolism and apoptosis, and PTEN has long been recognized as a tumour suppressor gene (Guldberg et al., 1997).