The main objective is to study and validate a new approach for NASH and liver fibrosis diagnosis and personalized follow-up based on monocyte biomarkers and plasma metabolites. The investigators will assess if PLIN2 and RAB14 can be used not only to identify subjects with NASH and advanced fibrosis but also for monitoring the effect of treatment alone or in combination with other metabolic parameters

Inclusion Criteria:

• Policlinico Universitario Agostino Gemelli IRCCS: Subjects with NASH documented by liver biopsy or fibroscan and no evidence of another form of liver disease with a BMI ≥ 30 and ≤40 kg/m2. Age 25-65 years.
• Coorte Azienda Ospedaliera Mater Domini: subjects with NASH documented by liver fibroscan aged >40 years with one or more cardiovascular risk factors,including overweight/obesity, elevated blood pressure, dyslipidemia, and dysglycemia
• Azienda Ospedaliero-Universitaria Policlinico Federico II: Subjects with NASH documented by fibroscan and no evidence of another form of liver disease. Age 25-65 years.

Exclusion Criteria:

• All units: Coronary event or procedure (myocardial infarction, unstable angina, coronary artery bypass, surgery or coronary angioplasty) in the previous 6 months; Liver cirrhosis; End stage renal failure; Participation in any other concurrent therapeutic clinical trial; Any other life-threatening, non-cardiac disease; Pregnancy; Inability to give informed consent; Substantial alcohol consumption (>20 g/day for women or >30 g/day for men); Wilson's disease; Lipodystrophy; Parenteral nutrition; Abetalipoproteinemia; Interfering medications (e.g., amiodarone, methotrexate, tamoxifen, corticosteroids).