Spatially upregulated genes that overlap between SZ and HZ (Figure 4) included an inhibitor of angiogenesis Adamts1[29], as well as matrix metalloproteinases Mmp9 and Mmp13, which are essential for endochondral bone formation [30] but also implicated in the pathophysiology of osteoarthritis [31], [32]. This evidence concerns the gene MMP13 and osteoarthritis.