MAP2K3 and neoplasm: In vivo results of tumor growth showed that MKK3 depletion per se significantly reduced tumor volume, compared with xenografts derived from control cells (sh/scr; Figure 6c, P<0.05); interestingly, MKK3 depletion further increased the effect of 5-FU on tumor growth (Figure 6c, P=0.01), in agreement with our hypothesis that MKK3 targeting could constitute a novel therapeutic strategy to improve tumor response to therapies.