PAK1 and neoplasm: We then quantified tumor burden at endpoint, Day 28, using BLI signal (Fig. 8a, b) and found a significant reduction in total tumor burden in mice injected with PAK1 knockdown cells (1.2 × 105 ± 0.8 radiance) compared to control cells (6.9 × 105 ± 1.8 radiance) (p = 0.02) (Fig. 8e).