Cellular viability of human skin cancer and normal human skin cell lines treated with RRM-designed peptides for 3 h measured by MTT assay. MM96L cells in (A), COLO-16 cells in (B), and HDF cells in (C) were incubated with different concentrations of RRM-MV or RRM-C for 3 h. Cells treated with 90% DMSO were used as positive controls. Results are reported as percentage of cell death, where the optical density (OD595nm) value from untreated cells was set at 0% of cell death. The bar graphs show mean ± standard error of three independent experiments. Statistical significance of the differences between RRM-MV-treated cells and untreated cells were analysed using one-way ANOVA and Tukey post hoc test. The cellular viability values of RRM-MV-treated melanoma and carcinoma cells were significantly different from those of untreated melanoma and carcinoma cells (P < 0.001).