There are three homologues: NANOS1, NANOS2, and NANOS3. Destroying NANOS1 in mice does not affect germ cell development, but knocking out NANOS2 or NANOS3 can lead to infertility, resulting in a decrease in gonadal size due to the loss of PGCs [26]. The gene discussed is NANOS2; the disease is Infertility.