DMP1 and Osteopenia: Considering that the Dmp1 promoter expression is detected in both calvariae and long bones75 and a comparable deletion efficiency of Kindlin-2 in both long bones and calvariae is observed in this study, it is unlikely that the osteopenia in load-bearing bones of cKO mice is due to a result of differential Kindlin-2 deletion between long bones and calvariae.