(A) Deletion of FAK (Ptk2) within the Prx lineage reduces proximal non–bone HO compared with mouse with single wt allele in Prx lineage by μCT imaging at 800 Hounsfield units (HU) (##P < 0.01, n = 6–9/group, Mann-Whitney U test). (B) Confocal microscopy images of Prx-Cre– and Prx-Cre+ deletion of FAK probed with indicated antibodies at 1 and 3 week time points after injury (left) quantified PDGFRα cell number, cell spread, and cell area (*P < 0.05, n = 2–4/group, n = 2–4 roi/mouse, n > 15 cells/image, Student’s t test). Scale bars: 100 µm. (C) FAK inhibitor (FAKi) PF573228 treated mice showed reduced total and distal HO at 800 HU 9 weeks after injury (***P < 0.001, n = 5/group, Student’s t test). (D) Inducible conditional deletion of YAP and TAZ coactivators within Hoxa11-expressing cells causes 50% reduction in ectopic bone formation Student’s t test (*P < 0.05, n = 2–3 mice/group).