Although obesity displays a chronic low-grade inflammation, the present study showed no BMI-related alterations in the frequencies of total NK cells and CD56dimCD16bright NK cells that are double-positive for CD158a+CD158b1/b2+, CD62L+CD158e/k+, CD57+NKG2A+, CD57+NKG2C+, and NKG2A+NKG2C+. The gene discussed is KLRC1; the disease is obesity due to melanocortin 4 receptor deficiency.