Single sample GSEA (ssGSEA) indeed revealed a dependency of tumors from NGFR (p75NTR)-mediated signaling and demonstrated a correlation of NGFR expression with brain metastasis in breast cancer68 (Fig. 4d, right panel, p < 0.05), suggesting that NGFRhigh melanoma are probably prone to brain metastasis. This evidence concerns the gene NGFR and melanoma.