The large number of genes involved in the pathogenesis of OI are FK506-binding protein 10 (FKBP10), peptidyl-prolyl isomerase B (PPIB), serpin peptidase inhibitor, clade f, member 1 (SERPINF1), wingless-type MMTV integration site family, member 1 (WNT1), bone morphogenetic protein 1 (BMP1), cartilage-associated protein (CRTAP), prolyl 3-hydroxylase 1 (P3H1), serpin peptidase inhibitor, clade h, member 1 (SERPINH1), and interferon-induced transmembrane protein 5 (IFITM5) (3, 4, 14–16). The gene discussed is PPIB; the disease is osteogenesis imperfecta.