CCL2 and melanoma: Furthermore, quantitative real-time PCR (qPCR) analysis of melanoma oncogenic genes (CD271, NES, AXL, LOXL2, MITF, MELANA, SOX10) and the melanoma chemotactic gene, CCL2, showed significant downregulation and a change in downstream signalling of these genes by glutamine supplementation in both PDX tumour models (Fig. 4g, h and Supplementary Fig. 2f)21,22.