ATP10A and Reduced sperm motility: In this study, we show that ATP10A protein is expressed in the vas deferens and testes of mice (Figure 1) and that Atp10A deficiency results in male-specific infertility characterized by small testes, oligozoospermia (due to low production or an inability for the sperm to diffuse efficiently out of the epididymal slices), and asthenozoospermia (Figure 2).