FNDC5 and gestational diabetes: Wawrusiewicz-Kurylonek’s group [128] analyzed the maternal serum irisin levels between 24 and 28 weeks of pregnancy and reported that pregnant women with GDM had a markedly lower irisin concentration than the normoglycemic (non-GDM) cohort (1679 (1308–2171) ng/mL vs. 1880 (1519–2312) ng/mL, respectively) [128].