MITF and metastatic neoplasm: In the tissue data of Riker et al. [16] the invasion signature genes correctly classified non-melanoma from melanoma tissue samples, and grouped primary and metastatic tumours as either Motif 1 and clustering with invasive A375 cell lines [24], or similar to higher MITF Motif 2 cell lines NZM12 and NZM15 (Figure S4).