LPL and obesity due to melanocortin 4 receptor deficiency: Interestingly, the seminal paper by Pietilainen et al. reported in monozygotic twins that obesity was associated with increases serum LPCs, including LPC(18:2), and decreases in serum ether lipids, which suggests that changes in LPL profiles are likely associated with genetic factors related with obesity rather than environmental and lifestyle factors31.