TRPM4 and melanoma: We validated these antibodies by numerous approaches, including immunoblots against HEK293 cells plus/minus expression of human TRPM4 (Supplementary Figures 1A,B), and by immunofluorescence labeling of COS-7 cells expressing FLAG-hTRPM4 (Supplementary Figure 1C) and B16-F10 murine melanoma cells transfected with a shRNA against TRPM4 that expresses GFP as an expression indicator.