MITF and melanoma: Given the fact that MITF levels confer phenotypic identity, and that MITF expression is suppressed by environmental and metabolic cues, it is not surprising that melanoma tumors, that are highly phenotypically heterogeneous, comprise different cells expressing variable levels of MITF that dictate their tendency to proliferate or invade (Goodall et al., 2008; Pinner et al., 2009).