Consistently, analyses of liver tissue and serum samples from healthy or NAFLD patients revealed that serum apelin levels were correlated (though not significantly) with TM4SF5 expression in the liver (p = 0.1746), with NAS (p = 0.0522), and with BMI (p = 0.1447), in addition to insulin resistance and higher cholesterol levels in NAFLD patients. Here, APLN is linked to neonatal abstinence syndrome.