To test this, we knocked down IFI6 in NRAS-mutant melanoma cell lines, YUGASP, M318, and SKMEL-103, and measured well-accepted markers of cellular senescence including senescence-associated β-gal (SA-β-gal) and acetylated histone H3K9 (H3K9Ac) (Narita et al., 2006, 2003). Here, NRAS is linked to melanoma.