KRT18 and metabolic dysfunction-associated steatohepatitis: The potential use of plasma M30 level as a non-invasive biomarker to determine histological disease severity in NAFLD subjects was first reported by Wieckowska et al. In their study of 44 consecutive subjects with suspected NAFLD at the time of liver biopsy, plasma CK-18 levels were markedly increased in adults with NASH compared to those with simple steatosis or normal liver biopsies.