MITF and melanoma: Moreover, although low levels of MITF are also associated with a higher hypoxia gene expression signature in the TCGA melanoma cohort (Figure S1c), consistent with previous work (Cheli, Giuliano, et al., 2011a; Feige et al., 2011) indicating suppression of MITF in vivo in response to low oxygen, some cell lines, such as IGR39, appear to exhibit a constitutive hypoxia signature (Figure 1e, Figure S1j), even though grown under normoxic conditions.