FABP4 and non-alcoholic fatty liver: FABP4 mRNA expression levels distinguished two subgroups of patients diagnosed by the pathologist as NAFL or NASH patients (Fig. 4B), but the ROC curves based on FABP4 expression levels also allowed distinguishing Control subjects from NAFL patients (specificity 0.714; sensitivity 1.000; AUC = 0.905) as well as Control subjects from NASH patients (specificity 1.000; sensitivity 0.875; AUC = 0.964) while no significant difference was observed between NAFL and NASH patients (specificity 0.853; sensitivity 0.750; AUC = 0.812, Fig. 4C).