Similar to Hyp entheses, C–/– entheses develop an expansion of SafO+, ALP+ cells that are immunoreactive for p-SMAD1/5/8, PTCH, and RUNX2 by P14, thus demonstrating that enthesopathy in both Hyp and C–/– mice develops early in the postnatal period. The gene discussed is SMAD1; the disease is enthesopathy.