Indeed, an investigation of the epigenetic regulation of the osteoarthritis susceptibility-containing gene GDF5 demonstrated that DNA methylation can affect the allelic expression imbalance between the C and T alleles of the GDF5 SNP rs143383, such that loss of methylation of the 5′UTR leads to a significantly greater imbalance in expression between the two alleles influencing their penetrance in susceptibility to osteoarthritis [241]. Here, GDF5 is linked to osteoarthritis.