KRAS and malignant colon neoplasm: To assess whether TP53 loss and mutated KRAS may affect intracellular and mitochondrial bioenergetics in this colon cancer cell model, we monitored cytosolic and mitochondrial ATP levels at single cell resolution, using ATP-sensitive FRET probes targeted to the cytosol (ATeam) or mitochondria (mitoATeam), respectively (Imamura et al., 2009).