The phosphatase and tensin homolog deleted on chromosome 10 (PTEN), also known as mutated in multiple advanced cancers 1 (MMAC1) and TGFß-regulated and epithelial cell-enriched phosphatase 1 (TEP-1) [1,2,3], is a well-known tumour suppressor gene located on chromosome 10q23.31 [2]. The gene discussed is PTEN; the disease is neoplasm.