To investigate the utility of the SigPath assay to detect and quantify acute perturbations in cell lines, we next treated LUAD H3122 cells with the ALK inhibitor ceritinib (Friboulet et al, 2014; Shaw et al, 2014) and KRAS mutant Ls513 colorectal cancer cells (CRC) with the MEK inhibitor trametinib (Falchook et al, 2012; Flaherty et al, 2012; Fig EV3A and B). The gene discussed is KRAS; the disease is colorectal cancer.