PSEN1 and melanoma: Our results showed that DAPT treatment of C8161, A375, and Sk-Mel28, in addition to the increased expressions of PS-1 and P-β-catenin shown above, also led to a significant reduction in cell migration compared with vehicle-treated control melanoma cells (C8161, −36% of control; A375, −46% of control; Sk-Mel28, −35% of control) (p < 0.05) (Figure 4A,B).