Within this context, the role of lipid-associated macrophages that express the triggering receptor expressed on myeloid cells 2 (TREM2) has gained prominence, particularly in diseases marked by lipid stress and inflammation, such as obesity, non-alcoholic steatohepatitis (NASH), and coronary atherosclerosis4,15,16. Here, TREM2 is linked to obesity due to melanocortin 4 receptor deficiency.