STAT3 and melanoma: In the context of immortalized melanocytes or human melanoma cell lines, we found that NRASQ61 had a greater ability to induce proliferation, migration and colony formation than NRASG12. This phenotypical difference was associated with a stronger STAT3 activation (and with an upregulation of STAT3 targets MMP2 and cMYC), when compared to NRASG12 (Figure 4A).