Table 1.

Definition of NAFLD Activity Score (NAS) Components.

Item	Extent	NAS
Steatosis	Steatosis at 50-fold magnification
	<5%	0
	5–33%	1
	>33–66%	2
	>66%	3
Lobular inflammation	Estimation of inflammatory foci
	No foci	0
	<2 foci/200x	1
	2-4 foci/200x	2
	>4 foci/200x	3
Ballooning	Estimation of number of ballooning cells
	None	0
	Few ballooning cells	1
	Many cells/prominent ballooning	2

NAFLD, Non-alcoholic fatty liver disease; NAS, NAFLD Activity Score.