Given the nature and goals of this study, possible hurdles that were expected to be encountered during our pursuit were the following: FD is a fibro-osseous lesion with a heterogeneous cellular and genetic makeup; it is a genetic disease characterized by various GNAS-mutant isoforms observed across patients; and it shows a dynamic tissue comprised of a wide spectrum of normal and mutant cells in variable proportions. Here, GNAS is linked to hereditary disease.