The Terc−/− inbred C57BL/6 mice exhibited premature reproductive aging and infertility with increasing generations (Keefe, 2016; Keefe & Liu, 2009), earlier than the original hybrid telomerase‐deficient mice (Herrera et al., 1999), and G2 Terc−/− C57BL/6 females already had reduced fertility and declined ovarian functions at young age, so here employed as premature aging mouse models. The gene discussed is TERC; the disease is Infertility.