Figure 4. Combined blockade of EGFR and STAT3 further enhances inhibition of cell viability. Wild-type K-Ras expressing colon cancer cells were treated in triplicate with (A) control, cetuximab, curcurbitacin, or a combination of both for 72 h and (B) control, erlotinib, curcurbitacin, or a combination of both for 72 h. Cell viability was determined as outlined above (*P < 0.05; ^#P < 0.01).