KRT18 and fatty liver disease: The NAFLD test was calculated in NAFLD patients and non-NAFLD controls; the performance of the test was compared with that of other non-invasive indices of NAFLD (fatty liver index [FLI] and hepatic steatosis index [HSI]), and other indices of NASH (index of NASH [ION] and cytokeratin-18/homeostasis model assessment-insulin resistance/aspartate transaminase index [CHAI]).