A similar classifier based on gene expression profiling in melanoma patients treated with HD IL-2 had previously reported greater response rates in tumors that expressed certain genes including Annexin A1, IL6R, oncostatin M, MCSF and GMCSF (class 2) compared to tumors that expressed MITF and melanocyte antigen expression (class 1) [31]; prospective validation of which is pending at this time. This evidence concerns the gene CSF1 and melanoma.