Previous studies using genetically engineered mouse models revealed that CatSper deficiency (Ren et al., 2001; Quill et al., 2003; Qi et al., 2007; Chung et al., 2011) or its altered function (Chung et al., 2017; Hwang et al., 2019) causes male infertility or subfertility due to the impaired sperm hyperactivation. This evidence concerns the gene CATSPER1 and male infertility.