MSMO1 is a known mediator of LH stimulation of cholesterol biosynthesis, whereas downregulation of VMA21, an essential assembly chaperone of the vacuolar ATPase (V-ATPase), was associated with induction of autophagy, ER stress and metabolic syndrome, contributing to the development of metabolic syndromes (Figure 2). This evidence concerns the gene VMA21 and metabolic syndrome.