HIF1A and osteoarthritis: The DEGs in the palovarotene-treated AcanCreER;Ext1f/f chondrocytes compared to those in control AcanCreER;Ext1f/f chondrocytes were strongly linked to the upregulation of the hypoxia-inducible factor 1a (HIF1a) signaling and osteoarthritis pathways (Figure 4B).