Despite the widely accepted view of the functional importance of mutations in cancer, the influence of protein expression levels is also important in tumorigenesis of CRC, including the expression of IDH2. Thus far, IDH2 has been shown to be overexpressed in endometrial (22), prostate and testicular cancers (23) as well as Kashin-Beck disease (24). Here, IDH2 is linked to Kashin-Beck disease.