For these three methylation sites, the direction of effect was concordant across tissues. Cg26736200 is annotated to the gene body of WWP2. Cg1755189 is located in the gene body of MAD1L1, a gene involved in cell-cycle regulation, which may point to cell senescence of chondrocytes in osteoarthritis articular cartilage.51 This evidence concerns the gene MAD1L1 and osteoarthritis.