COL1A1 and polyostotic fibrous dysplasia: Reduced mRNA levels of Elastin, Col1a1 and Col3a1 were observed in PFD rats when compared to NC group (p = 0.0026 for Elastin; p = 0.0044 for Col1a1; p = 0.0101 for Col3a1) (Figures 4A and 5C).