PLIN2 and obesity due to melanocortin 4 receptor deficiency: These organelles are composed of a hydrophobic neutral lipid core surrounded by a phospholipid monolayer membrane, which contains numerous proteins related to cellular activation in addition to structural proteins, such as perilipin 2 (PLIN2), which plays an important role in LD assembly and the formation of foam macrophage [213], marker cells in metabolic diseases, such as atherosclerosis and obesity [214].