MITF and melanoma: Consistent with MITF heterogeneity being present in invading cells, MITF staining revealed that MITFhigh and MITFlow cells coexist in groups of melanoma cells invading the dermis (Figure S5A), which is also apparent in other published data (King et al., 1999) and in biopsy samples displayed in the Human Protein Atlas http://www.proteinatlas.org (Uhlen et al., 2010; Figure S5B).