PTEN and cancer: Altered gene expression is a hallmark of cancer, from down regulation of tumor suppressor genes (e.g., PTEN, BRCA1, CDKN2A, RASSF1, HIC1) to upregulation of oncogenes (e.g., GRN, FHL2, CNKSR1) [183,184,185,186,187,188,189,190].