IDH2 and chondrosarcoma: Using immunohistochemistry as a surrogate for mutation analysis, we show that SDH and FH mutations are not involved in the subset of chondrosarcomas that are wildtype for IDH. Moreover, it is unlikely that mutations in TET2 are playing a prominent role in chondrosarcoma, since Tarpey et al. demonstrated TET2 mutations in only one out of 49 (2%) chondrosarcomas subjected to whole-exome sequencing [47].