As shown in Figure 3A (left panel), GTPs treatment of A375 melanoma cells resulted in significant inhibition of HDAC activity (6-25% at 24 h, and 13-47% at 48 h; P<0.05 to P<0.001) as compared with vehicle-treated control cells and that this inhibitory effect of GTPs was dose- and time-dependent. This evidence concerns the gene HDAC9 and melanoma.