Model of chondroma-like lesion formation in <i>Fgfr3</i> cKO mice.

<p>(<b>A</b>) Effect of <i>Fgfr3</i> deficiency on chondroma-like lesion formation. (<b>B</b>) Schematic of normal growth plate in long bone. Growth plate chondrocytes are well-organized and surrounded by the perichondrium. (<b>C</b>) Loss of <i>Fgfr3</i> in growth plate chondrocytes leads to changes in signaling and in chondrocyte polarity, proliferation, differentiation, and apoptosis, resulting in the formation of chondroma-like lesions. (<b>D</b>) Growth plate chondrocytes near the perichondrium subsequently form osteochondroma-like lesions, while those in middle region form enchondroma-like lesions. RZ, resting zone; PZ, proliferative zone; PHZ, pre-hypertrophic zone; PZ, hypertrophic zone; TB, trabecular bone; GR, groove of Ranvier.