PDHK4 mRNA has been shown to be upregulated in response to glucose deprivation and fatty acid supplementation; manifestations which occur in patients with insulin resistance, obesity and type 2 diabetes.28 In order to determine whether the observed phenotypic effect on cell growth in mutant KRAS cells after PDHK4 depletion was conferred by a metabolic switch, we first performed a targeted fluidigm expression analysis of the most relevant genes involved in different metabolic pathways in the isogenic HCT116 cells. The gene discussed is PDK4; the disease is obesity due to melanocortin 4 receptor deficiency.