PTEN and non-small cell lung carcinoma: PTEN is frequently deficient in several malignancies because of mutations or epigenetic changes [68,69] In addition evidences has also been provided supporting that CpG islands of the PTEN promoter are methylated in several type of human cancers, such as endometrial carcinoma [70], gastric [71], non-small-cell lung carcinoma [72] and cervical cancer [73].