NRAS and melanoma: Signature genes characterizing a pigmentation (MITF high) subtype of melanomas taken from the study of Jönsson and coworkers show bipolar activation patterns in the present study with high levels in wt/wt cells and low levels in BRAF-wt/NRAS-mut cells and an intermediate, fluctuating levels in BRAF-mut/NRAS-wt cells [6] (Figure 2B).