To characterise the expression of Snail1 in melanoma, and to distinguish tumour cells from the cells in the TME, we generated a melanoma reporter mouse model by crossing the inducible BRAF-driven mouse melanoma model BrafCA,PtenloxP,Tyr::CreERT2 (BrafV600E/PtenloxP) [26] with Rosa-LSL-tdTomato mice (tdTomato). The gene discussed is SNAI1; the disease is melanoma.