IDH2 and Thiamine deficiency: Although the activities of GDH, OGDHC and NAD+-dependent IDH are not changed by thiamine deficiency in A549p21– cells, the level of GOT2 is increased 5-fold in the A549p21– cells (Figures 4A–E), along with a small, but statistically significant upregulation of NADP+-dependent ME and IDH.