CYP26B1 and Osteochondroma: The expression of cytochrome P450 family 26 subfamily member 1 (Cyp26b1), a genomic target molecule of the retinoid signaling pathway, was upregulated in the osteochondroma region in the periphery of the growth plate of palovarotene-treated AcanCreER;Ext1f/f mice (Figure 5B vs. Figure 5C), indicating that osteochondromas responds to palovarotene.