By monitoring the cytosolic NADH/NAD+ ratio in a transgenic mouse model engineered to express a highly responsive fluorescent NADH/NAD+ sensor as well as in primary human B cell acute lymphoblastic leukemia (B-ALL) cells, increased rates of oxidative phosphorylation were detected, presumably maintained by the function of the pyruvate dehydrogenase complex component X (PDHX), which facilitates the entry of pyruvate into the TCA cycle [13]. This evidence concerns the gene PDHX and B-cell acute lymphoblastic leukemia.