The analysis of this series of early passage human melanoma lines has shown them to be highly heterogeneous not only with respect to expression of proteins directly associated with EMT such as E-cadherin, Snail, Slug, and Axl (Figure 1) but also with respect to expression of proteins that are more indirectly associated with EMT, such as MITF and p53 (Figure 3). This evidence concerns the gene SNAI2 and melanoma.