Notably, we did not observe a significant interaction between fish oil use and overall GRS on the risk of developing T2D (P interaction = 0.186) (Table S4), whereas there was a significant interaction between fish oil use and rs780094 in GCKR (P interaction = 0.049) and marginal interactions were found for rs174555 in FADS1 (P interaction = 0.078), rs7200543 in NTAN1 (P interaction = 0.061), and rs102275 in TMEM258 (P interaction = 0.072) (Table S5), indicating that DHA/EPA metabolic pathways may play a role in the beneficial effect of fish oil. This evidence concerns the gene TMEM258 and type 2 diabetes mellitus.