PKM and Hepatic fibrosis: Follistatin-like protein 1 (FSTL1) is thought to be a proinflammatory gene involved in macrophage polarization that accelerates the progression of liver fibrosis by promoting pyruvate kinase M2 (PKM2) phosphorylation and inhibiting PKM2 ubiquitination in macrophages, thereby increasing M1 polarization, glycolysis, and inflammatory responses [26].