TNF and obesity due to melanocortin 4 receptor deficiency: Serum TNF-α was 5.5 ± 0.6 pg/ml in HFD- fed C57BL/6J mice (P < 0.01) vs 2.6 ± 0.3 pg/ml in SRC-fed C57BL/6J mice and was 6.7 ± 0.8 pg/ml in HFD- fed KKAy mice (P < 0.01) vs 3.2 ± 0.4 pg/ml in SRC-fed KKAy mice (Figure 4C), indicating a role of overweight- or obesity-associated inflammation in carcinogenesis.