To gain insight into the possible interplay between SOX10 and SOX9 during tumor progression, we quantified the expression levels of SOX10 and SOX9 in normal human melanocytes, in cells from giant congenital naevi, and in a melanoma cell line (M010817; [49]) using quantitative RT-PCR analysis (Fig. 4A-C). This evidence concerns the gene SOX9 and melanoma.