FOXD2 and osteoarthritis: FOXD2-AS1 (human ortholog of Foxd2os) is known to be highly expressed and regulates chondrocyte proliferation in patients with osteoarthritis.28,29 We next compared the gene expression changes between Xe1 and Xe1+PEC7 homozygous female mice, as Xe1 homozygous mice do not have a kinky tail sex bias phenotype.