CCL2 and obesity due to melanocortin 4 receptor deficiency: Interestingly, although no significant variation in cytokine, chemokine and growth factor secretion was found, IL-6 and MCP-1 secretion, well-known pro-inflammatory cytokines involved in the etiology of obesity- and diabetes-related diseases [26], seemed to be slightly increased upon BPA treatment, while IL-1ra, with anti-inflammatory activity, a natural inhibitor of the pro-inflammatory effect of IL1β, had a trend in reduction.