Fig. (2) Pyogenic granuloma-derived cells. A) After the initial seeding, many cells attached to the plates in an acceptable fibroblast-like (fusiform) appearance. These cells reached confluence within 12-21 days. B) A single cell derived colony from pyogenic granuloma-derived cells formed within the CFU-Fibroblast assay. C) Lipid vacuoles stained with Oil Red O stain after adipogenic differentiation. D) Osteogenic differentiation with calcium deposition identified by Alizarin red staining. (Abbreviations: CFU-F = Colony forming unit fibroblast).