NRAS and melanoma: Although the levels of mutant N-RAS expression in all of the melanoma isolates were not significantly different, the ability of [neratinib + valproate] to reduce N-RAS expression varied with TPF-3-84 and TPF-14-405 presenting with a significantly lower N-RAS down-regulation effect compared to the down regulation effect in TPF-15-232 and TPF-16-76 (Figure 3B, lower).