IL6 and obesity due to melanocortin 4 receptor deficiency: It is well known that obesity-triggered chronic low-grade inflammation negatively affected the male reproductive system, following disruption of semen parameters and testicular steroidogenesis with decreased key steroidogenic enzymes (StAR, P450scc, 3β-HSD and 17β-HSD) under the increasing concentrations of inflammatory cytokines (IL-1, IL-6, and TNF-α) in the testis [62, 63].