SERPINE2 and melanoma: We therefore merged two clusters with high expression of mesenchymal markers (Dcn, Col1a1, Col1a2), merged five clusters with high expression of neural crest/neuronal genes (Nes, Foxd3, L1cam, Ngfr), and then merged the remaining three clusters which had high expression of the genes Fosb, Klf4, Serpine2, Cdkn1a from a published metastatic melanoma gene set (Perego et al. 2018).