Main mechanisms connecting both obesity and T2DM to BC include adipokines, hormones and growth factors (i.e. insulin, insulin-like growth factors and estrogen), hyperglycemia, dyslipidemia, hypoxia-dependent gene transcription, sustained activation of pro-tumorigenic inflammatory mediators and immune function dysregulation [5, 68, 70]. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.