Wang C, et al. - A metabolome-wide association study (MWAS) was conducted to systematically examine the impacts of genetic variants on metabolites and lung cancer based on published GWASs and metabolic-quantitative trait loci (mQTL) study. The present data indicated that rs174548 was associated with both polyunsaturated fatty acids (PUFAs) and lung cancer. The findings suggested that plasma PUFAs could be causally correlated with lung cancer based on the idea of Mendelian randomization. These discoveries provide a diet-related risk factor and may have important implications for prevention of lung cancer.