In another case, it was shown that TDEs from 5-fluorouracil (5FU)-resistant colorectal cancer (CRC) were enriched in the enzyme isocitrate dehydrogenase 1 (IDH1), which catalyzes the reversible reaction of converting isocitrate and NADP+ to αKG and NADPH [249,250]. The gene discussed is IDH1; the disease is colorectal carcinoma.