A) HT-29 cells treated for 96 hours, 10 μM erlotinib, 1 μM MI-2–2. B) HT-29 cells treated for 48 hours, 10 μM gefitinib, 1 μM MI-463. C) HT-29 cells transduced with lentiCRISPRv2 vector or menin sgRNA, with clones (c1 and c2) selected lacking menin expression, then treated for 48 hours, 10 μM gefitinib. D) HT-29 cells treated for 24 hours, 10 μM gefitinib. E) SW620 cells treated for 96 hours with varying concentrations of gefitinib, with HT-29 cells as a control for p-EGFR/EGFR expression.