As opposed to p107+/−/p130−/−/RbLox/Lox/α-MHC-Cre+/− (Hetp107/KOp130/KOαMHC-Rb, H/K/K) and p107−/−/p130+/−/RbLox/Lox/α-MHC-Cre+/− (KOp107/Hetp130/KOαMHC-Rb, K/H/K) mice, which survive to adulthood, 3KO pups were stillborn or died at E14.5–E15.5 from heart failure as manifested by large pericardial effusions and anasarca. The gene discussed is RB1; the disease is heart failure.