MSH3（mutS homolog 3），癌症关联基因，基因ID：4437，该基因编码的蛋白质与msh2形成异二聚体，形成mutsβ，是复制后dna错配修复系统的一部分。mutsβ通过与失配结合并与mutlα杂二聚体形成复合物来启动失配修复。该基因在第一个外显子中含有一个多态的9bp串联重复序列。在参考基因组序列中，重复出现6次，已有3-7次报道。这个基因的缺陷是子宫内膜癌易感性的一个原因。[由RefSeq提供，2011年3月]The protein encoded by this gene forms a heterodimer with MSH2 to form MutS beta， part of the post-replicative DNA mismatch repair system. MutS beta initiates mismatch repair by binding to a mismatch and then forming a complex with MutL alpha heterodimer. This gene contains a polymorphic 9 bp tandem repeat sequence in the first exon. The repeat is present 6 times in the reference genome sequence and 3-7 repeats have been reported. Defects in this gene are a cause of susceptibility to endometrial cancer. [provided by RefSeq， Mar 2011]。