RNF20 and female infertility: Intact primordial, primary, secondary, and antral follicles were all observed in Rnf20Flox/Flox and Zp3‐Rnf20−/− ovaries (Figure S2G,H, Supporting Information), which suggests that female infertility may not be caused by the failure of follicular development but rather by defective oocyte meiotic maturation.