CATSPER2 (cation channel, sperm-associated 2): CATSPER2 is crucial for sperm motility and fertility, as it is part of the complex calcium channel in sperm necessary for the hyperactivated motility required for fertilization. Mutations in CATSPER2 can result in male infertility due to impaired sperm function. Research on CATSPER2 offers insights into reproductive health and potential targets for contraception or infertility treatment.