KRAS and neoplasm: We found that [18 F]FDG uptake was reduced in a dose (0.3-1.3 μM) - and time (0-48 h) - dependent manner in HCT116 and COLO205 tumor cells carrying K-ras and B-raf mutations, respectively, whereas RO5126766 did not affect [18 F]FDG uptake in COLO320DM cells, which has no mutation in these two genes and no apparent levels of phospho-MEK and phospho-ERK in the cells.