We have recently shown that a 12 week-long HFD feeding induced obesity in both control and LysM-GRK2+/- animals to the same extent but only deteriorated glucose tolerance, caused hyperglycemia, and provoked insulin resistance and inflammation in liver and adipose tissue in control mice, while LysM-GRK2+/− animals maintained smaller adipocytes [23]. Here, GRK2 is linked to obesity due to melanocortin 4 receptor deficiency.