In our previous study, we have reported that germ-cell specific removal of Cul4b (Cul4bVasa) led to male infertility due to spermiogenesis defects, whereas global Cul4b knockout mice (Cul4bSox2) exhibited an age-dependent germ-cell depletion phenotype [12]. The gene discussed is CUL4B; the disease is male infertility.