To investigate the cytotoxic activity of Psd1 on tumor cell viability, MTT-based colorimetric assays were performed using murine skin melanoma (B16F10), human epidermoid carcinoma (A-431), and healthy (Beas-2B, HEK, R8, HSP, and CHO) cell lines (Figure 1). This evidence concerns the gene PSD and cutaneous melanoma.