Abstract: Methods, compositions, kits, and systems for characterizing the non-alcoholic fatty liver disease (NAFLD) state of a subject are provided. In some embodiments the methods, compositions, kits, and systems comprise at least one miRNA selected from the differentially expressed miRNAs listed in at least one of Tables 1-4, 10-14, and 28-29. In some embodiments the methods compositions, kits, and systems are for characterizing the nonalcoholic steatohepatitis (NASH) state of the subject, characterizing the occurrence of liver fibrosis in the subject, and/or characterizing the occurrence of hepatocellular ballooning in the subject.