A leptin G-2548A gene polymorphism in the promoter region of leptin gene has been shown to correlate with variations in serum leptin levels, degree of obesity, as well as cancer susceptibility and has been shown in several reports to promote tumor growth.43,44 A broad range of investigations have demonstrated strong evidence for an involvement of leptin in breast cells proliferation stimulation, apoptosis inhibition, cell migration, and angiogenesis.45–48. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.