MSH4 and Infertility: Referring to the mouse studies, we can infer that MSH5 is also likely to be a prerequisite for MSH4 recruitment and retention on the axes in human spermatocytes, and that the infertility outcome in the patient carrying the MSH5 mutation (c.1126del) is supposed to be caused by the abolished axial localization of both MSH4 and MSH5.