This is the first follow-up study demonstrating the liver specific effects of 18-months treatment with DHA in pNAFLD which (i) improves hepatic steatosis, ballooning, inflammation NAS and PNHS scores but was ineffective on fibrosis; (ii) causes a remarkable reduction of DR and HPC activation strongly associated with NAS and PNHS scores; (iii) induces a reduction of GPR120-positive inflammatory MΦ/KCs and an increase of GPR120-positive hepatocytes; and (iv) downregulates nuclear translocation rate of phosphorylated form of p65NF-κB in hepatocytes and liver macrophages. The gene discussed is FFAR4; the disease is fatty liver disease.