Here, we evaluated the clinical and histomorphologic features and expression patterns of mTOR, phosphorylated STAT3 (pSTAT3), phosphorylated ERK (pERK) and estrogen-receptor α in hepatocytes and hepatic stellate cells in liver tissue from patients with hepatic steatosis, along with a control group (biliary cysts and hepatolithiasis). The gene discussed is STAT3; the disease is fatty liver disease.