To gain insight into the possible cellular mechanism(s) by which TNF maintained its effect, we recapitulated melanoma in an in vivo-like [32,33] skin equivalent (SE) model, which is an alternative to animal models, using sorted quiescent (GFPhigh) and fast-cycling (GFPlow) cells in the presence or absence of systemic TNF for 3 weeks. Here, TNF is linked to melanoma.