As a result, when sperm were incubated in capacitating conditions, the intracellular protein tyrosine phosphorylation level was increased in wild-type sperm, but no increase was apparent in Slc22a14−/− sperm (Fig. 5d), indicating that neither motility nor capacitation is normal in Slc22a14−/− sperm and that these synergistic effects cause severe infertility in Slc22a14-deficient mice. The gene discussed is SLC22A14; the disease is Infertility.