As such, this data does not offer an explanation as to why A549 cells are the least sensitive cell line to GDC-0980 treatment, however we hypothesize that either the high expression of a panel of cancer drug resistance genes identified in A549 cells, or the preferential signalling through KRAS due to KRAS mutation may help to reduce the efficacy of these inhibitors. The gene discussed is KRAS; the disease is cancer.