HMGB2 and Hypoglycemia: Hmgb1−/− mice die shortly after birth because of hypoglycemia (Calogero et al. 1999; Rovere-Querini et al. 2004), while hmgb2−/− mice are viable, but male mice have reduced fertility, as HMGB2 seems to play a role in germ cell differentiation (Ronfani et al. 2001).