Table 1. NASH Clinical Research Network histological scoring system.

NAFLD activity score	NASH fibrosis stage
Steatosis  < 5%: 0  5–33%: 1  34–66%: 2  > 66%: 3 Lobular inflammation  None: 0  < 2: 1  2–4: 3  > 4: 4 Ballooning of hepatocytes  None: 0  Few ballooned: 1  Many ballooned: 2 NAS score (0–8)  < 3: not NASH  ≥ 5: NASH	Stage 0  No fibrosis Stage 1  Zone 3 perisinusoidal fibrosis Mild – 1a Moderate – 1b Portal/periportal – 1c Stage 2  Perisinusoidal and portal/periportal fibrosis Stage 3  Bridging fibrosis Stage 4  Cirrhosis