PTEN and rectum neuroendocrine neoplasm: Similarly, mutated genes such as TP53, phosphatase and tensin homolog (PTEN), cyclin dependent kinase inhibitor 2A (CDKN2A), F-box and WD repeat domain containing 7 (FBXW7), and AKT serine/threonine kinase 1 (AKT1) have been detected in rectal NETs (13, 14).