To determine whether CD36 expression in the human liver is increased by the physiological process of aging, immunohistochemical staining for CD36 was performed in liver biopsy samples from young (20-38 years) and aged individuals (50-83 years) with histologically normal livers, and liver biopsy samples from young (20-42 years) and aged individuals (52-74 years) diagnosed with non-alcoholic steatosis (NAS) (Fig. 1A). This evidence concerns the gene CD36 and neonatal abstinence syndrome.