The effect of ERK2 and pERK2 expression on survival. Patients were divided into 2 groups on the basis of ERK2 expression, lower one third versus higher two thirds, on the basis of retrospective study data. Likewise, patients were divided into 2 groups, lower two thirds versus higher one third, on the basis of the level of pERK2 expression and retrospective study data. These were combined to form 4 groups for ERK2 and pERK2 (low/low, low/high, high/low, and high/high), and the Kaplan-Meier survival curves are shown here. The P value shown is for the plot of all 4 curves. P = .002 for the comparison of those with low/low ERK2 and pERK2 with those with one or both high.