MAFB and melanoma: Surprisingly, a single injection of E. coli–sgMafb/Maf was sufficient for eradicating the majority of melanoma tumors in the liver and greatly improved the survival rate of tumor-bearing mice, from 30% to 90% (Figure 4, D–F), whereas disruption of either Mafb or Maf alone exhibited only a moderate reduction in hepatic tumor burden (Supplemental Figure 13, A and B).