To assess the heterogeneity of the McSC-initiated murine melanomas after phenotypic switch, we transplanted McSCs from Tyr-CreER:Braf:Pten:Tomato mice, induced transformation and compared gene expression of resultant melanoma cells from 3 recipients to untransformed McSCs by single cell RNA-seq (Fig. 5a). This evidence concerns the gene PTEN and melanoma.