These characteristics lead to a proposal that the RASSF1A isoform is the major tumor suppressor gene inactivated in many kinds of tumors by promoter methylation, which is the major mechanism for inactivation of RASSF1A since an observation of point mutation in RASSF1A gene was found to be a rare event in a majority of human cancers[24]. Here, RASSF1 is linked to cancer.