In addition, a novel NASH-specific macrophage population (termed NAM) was identified, suggesting that NASH alters the functional properties of liver macrophages populations by increasing Trem2 protein levels in a subset of macrophages, therefore increasing liver heterogeneity during pathogenesis of NASH (Xiong et al. 2019). This evidence concerns the gene TREM2 and metabolic dysfunction-associated steatohepatitis.