However, a wealth of studies now demonstrate that CatSper is a key determinant of sperm motility and fertilisation competence (Alasmari, Costello, et al., 2013; Brown et al., 2018; Kelly et al., 2018; Ren et al., 2001; Smith et al., 2013; Strünker et al., 2011; Williams et al., 2015) and therefore represents a plausible target for the development of novel therapeutics for male infertility. The gene discussed is CATSPER1; the disease is male infertility.