To investigate the splicing level of XBP1 in melanoma cells, we analyzed mRNA levels of the spliced form of XBP1 (XBP1s) in a group of cell lines containing normal melanocytes (HEMn-MP and HEMn-DP) and melanoma cells (Mel-RMu, MM200, Mel-CV, IgR3, A2058 and SkMel-28). The gene discussed is XBP1; the disease is melanoma.