Ca2+ regulates the anti-melanoma effect of aspirin. (A,B) (A) A375 and (B) A2058 cells were treated with the indicated concentrations of aspirin (ASA) in the absence or presence of BAPTA-AM (30 µM) and EGTA (0.2 mM) for 72 h and analyzed for viability by the WST-8 assay. Data represent the mean ± SD (n = 3). ### p < 0.001; n.s., not significant vs. control. * p < 0.05; *** p < 0.001. (C,D) (C) A375 and (D) A2058 cells were treated with aspirin in the absence or presence of BAPTA-AM (30 µM), EGTA (0.2 mM), and nifedipine or verapamil (1 µM) for 72 h and analyzed for viability as described above. Data represent the mean ± SD (n = 3). *** p < 0.001.