IDH1 and chondrosarcoma: In summary, both short term as well as long term continuous inhibition of endogenous mutant IDH1 in three different chondrosarcoma cell lines show that although D-2-HG levels are decreased by the treatment, there is no significant effect on proliferation, migration (both in monolayer as well as in 3D), CpG island methylation or histone trimethylation of H3K4, H3K9 and H3K27.