YAP1 and liver cancer: Moreover, the expression of YAP in well-differentiated (G1) liver cancer tissues was significantly lower than that were moderately (G2) (P = 0.003) and poorly ( G3) (P < 0.001) differentiated, and the levels of YAP were significantly higher in G3 samples in contrast to G2 samples (P < 0.001) (Additional file 1: Fig. S1C).