With no evidence of increased germ cell apoptosis in the Katnal11H/1H mutant, and with epididymides filled with immature germ cells, we can conclude that KATNAL1 function is essential for retention of spermatids during spermiogenesis, and that fundamental failure at this specific stage of spermatogenesis is the primary cause of the observed infertility phenotype. Here, KATNAL1 is linked to Infertility.