To clarify this issue, this unique and multistage study systematically examines the molecular changes associated with SIRT1 overexpression in leukocytes from a group of clinically well-characterized diabetic pregnancies displaying homogeneous leukocyte SIRT1 expression (i.e., the GDM/SIRT1(↑) group) at the time of GDM diagnosis. The gene discussed is SIRT1; the disease is gestational diabetes.