(a) The proteins levels of these five genes in various human melanomacell lines, normal human melanocytes (NHEM), and normal human keratinocytes (NHEK) were analyzed by western blot using specific antibodies to these five proteins. β-Actin served as loading controls. Each experiment was carried out three times. Blots shown are representatives from three experiments. (b) and (c) The effectiveness and specificity of siRNAs against GNPAT, SUMO1, SPINT2, FLI1, and SSX1 to downregulate targeting gene expression were demonstrated on both mRNA and protein levels by RT-PCR (b), western blot (b), and IHC (c) in A375 cells. In (c), two sets of siRNAs targeting different areas of the mRNA were selected to test for each gene.