(A) Representative H and E and phospho-ERK1/2 immunostaining photomicrographs of paraffin-embedded lung sections from BrafLSL-V600E/+;Trp53f/f;Nkx2-1f/+;Rosa26LSL-tdTomato/LSL-tdTomato and BrafLSL-V600E/+;Trp53f/f;Nkx2-1f/f;Rosa26LSL-tdTomato/LSL-tdTomato mice that were treated with control chow (BP C/BPN C) or chow containing PLX4720 (200 mg/kg) and PD0325901 (7 mg/kg) inhibitors (BP Tx/BPN Tx) for 2 weeks starting at 6 weeks post-tumor initiation with PGK-Cre lentivirus (5 × 103 pfu/mouse). Here, MAPK3 is linked to neoplasm.