In this study, we demonstrate that conditional Fgfr3 knockout (Fgfr3 cKO) mice lacking FGFR3 in chondrocytes exhibit severe enchondroma- and osteochondroma-like lesions in the skeleton, indicating that FGFR3 is critically involved in the formation of cartilaginous tumors. The gene discussed is FGFR3; the disease is chondrogenic neoplasm.