KRT1 and neoplasm: After 4 weeks, each of the four mice injected with K1-NC cells developed a small tumor (tumor volume < 0.5 cm3), whereas each of the four mice injected with YAP1-overexpressing K1 cells grew a large tumor (tumor volume > 1.0 cm3) (Figure 3C), indicating that the latter cells were more tumorigenic than the former.