Although cubic relationships between BMI and the effect sizes of marine-derived n-3 PUFAs supplementation on the level of CRP and TNF-α in subjects with chronic non-autoimmune disease were not significant, subgroup analysis found a similar result: marine-derived n-3 PUFAs supplementation had a significant lowering effect on CRP and TNF-α in subjects with a BMI less than 30 kg/m2 but not in subjects with a BMI ≥30 kg/m2, and the subgroup difference was significant. The gene discussed is CRP; the disease is autoimmune disease.