Dissecting Therapeutic Resistance to ERK Inhibition Rat Wild Type SCH772984 in complex with (3R)-1-(2-oxo-2-{4-[4-(pyrimidin-2-yl)phenyl]piperazin-1-yl}ethyl)-N-[3-(pyridin-4-yl)-2H-indazol-5-yl]pyrrolidine-3-carboxamide