The mechanisms of thisregulation, which may be impaired in tumors, have not been studied.Indeed, PTENP1 pseudogene deletions have been found insporadic rectal tumors [28], as well asin primary and metastatic melanoma [31].Another potential mechanism of PTENP1 pseudogene inactivationby methylation of its promoter region was identified in lung cancer [32] and, recently, in clear cell renal cancer[33]. This evidence concerns the gene PTENP1 and rectal neoplasm.