WNT1 and osteogenesis imperfecta: We identified 11 strains of OI mice that mimic diverse types of causative gene mutations, including OI mice with Col1a1 mutation (Col1a1Jrt1/+, Brtl−/−), OI mice with Col1a2 mutation (G610C+/−, Oim−/−, Oim+/−), Wnt1 mutation (Wnt1prrx1−/−, Wnt1sw/sw, Wnt1+/G177C, Wnt1G177C/G177C), and other OI-associated mutations (Crtap−/−, Bril−/−).