Similarly, serum niacin was reduced in individuals carrying the PNPLA3 CG/GG mutation (p < 0.05 at Wilcoxon, adj p = 0.03 vs PNPLA3 CC, Figure 1C) although no significant differences in its levels emerged among patients with steatosis < 2 and ≥ 2 (Supplementary Figure 1A), possibly suggesting that the presence of the rs738409 C > G PNPLA3 genotype rather than hepatic fat accumulation may influence niacin absorption or metabolism. This evidence concerns the gene PNPLA3 and steatosis.