TWIST1 and melanoma: As a cell of tumor origin does not necessarily have to be a CSC, it is reasonable to assume that there must be a way for cancer cells to acquire stem cell traits.35 To this end, the developmental program of EMT has been reported to confer pro-invasive as well as stem cell-like properties to cancer cells.4, 36 Similarly, the EMT-mediating transcription factor Twist1 has been shown to be crucial to melanoma initiation and progression.37