Consistently, the homologs of these five regionalized genes are associated with various developmental, homeostatic, and disease processes in mammals (e.g., Creb3l1 with osteogenesis imperfecta [33], Kmt2d with Kabuki syndrome [34], Smad1 with the control of cell fate [35], Mzf1 with keratinocyte differentiation [36], and Foxa2 with cholestatic syndromes [37]). Here, SMAD1 is linked to osteogenesis imperfecta.