背景资料:RASSF1A is a protein similar to the RAS effector proteins. Loss or altered expression of the RASSF1A gene has been linked to the pathogenesis of a variety of cancers, which suggests the tumor suppressor function of the RASSF1A gene. The inactivation of the RASSF1A gene was found to be interconnected with the hypermethylation of its CpG-island promoter region. The RASSF1A protein was found to interact with DNA repair protein XPA. RASSF1A was also shown to inhibit the accumulation of cyclin D1, and thus induce cell cycle arrest.