In the case of the serum FGF21 levels, however, there were no statistically significant differences across the three groups [T2D-R: 540.55 pg/mL, T2D-NoR: 842.24 pg/mL, No-T2D: 393.28 pg/mL, (Kruskal-Wallis Chi Square Test: 4.39, P-value = 0.1111)] despite the fact that the two diabetes groups had higher FGF21 serum levels. The gene discussed is FGF21; the disease is type 2 diabetes mellitus.