While some of these PFD are caused by pathogenic RUNX1 mutations (PFD‐RUNX1), others are caused by uncharacterized molecular defects that manifest with nonsyndromic DGD (PFD‐DGD) or impaired aggregation responses to multiple agonists (PFD‐OTH).3 The gene discussed is RUNX1; the disease is polyostotic fibrous dysplasia.