PON1 and endometrial cancer: PON3 is a member of the paraoxonase (PON) gene family characterized by antioxidant properties.[56] It has been established that in endometrial cancers, MSI events are more frequent in the 3′ untranslated region of PON3, than in CRC.[57] As in the case of DCD, little is known regarding the association between the MSI events and gene expression of PON3.