To evaluate the role of FGF21 in gestational diabetes mellitus (GDM), we collected visceral fat samples from three groups: non-pregnant chow diet female mice (ND-Virgin), pregnant chow diet female mice (ND-E18.5), and pregnant high-fat high-sucrose diet female mice (GDM-E18.5) (Figure 1A). The gene discussed is FGF21; the disease is gestational diabetes.