IDH1 and cancer: With reprogramming of glutamine metabolism from the mitochondrial to the cytoplasmic system, cancer cells are able to keep FA synthesis intact: glutamine contributes to lipogenesis and cell growth in cancer cells via another non-canonical cytoplasmic glutaminolysis pathway with isocitrate dehydrogenase (IDH1, catalyzes α-KG/isocitrate) under hypoxia, or even with defective mitochondria [40,41,42].