Aberrant CIITA expression in melanomas results from the activation of both IFNγ-inducible and constitutive CIITA promoters, and deletion of the same AP-1 site that we found differentially occupied by Jun in Fbw7 mutant Hct116 cells compromised CIITA expression in melanoma cells (van der Stoep et al., 2007). The gene discussed is JUN; the disease is melanoma.