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