FGF18 and bone disorder: Fibroblast growth factors (FGFs) are important and relevant growth factors in cartilage development.37 Among them, FGF2 and FGF18 have been confirmed to participate in cartilage remodeling.38 However, FGF20 was also recently proven to regulate the proliferation of chondrocyte progenitors and promote mesenchymal condensation.39 This study also provides new clues for the roles of Runx1 and FGF20 in skeletal disease occurrence.