LCN2 and obesity due to melanocortin 4 receptor deficiency: At the crossroads of several OA risk factors, such as obesity, altered mechanical loading, joint inflammation and ageing, is lipocalin-2 (LCN2)5, 16, a mechanoresponsive adipokine induced by pro-inflammatory factors in joint tissues, whose circulating levels are elevated in obese and aged individuals5, 17, 18, 19.