Th1 cells play a pathogenic role by activating macrophages and cytotoxic T-cells, and secrete some interleukins such as IL-2 and interferon gamma (IFN-γ), while Th2 cells induce the production of interleukins (IL-4 and IL-10) that play a protective role during GDM. The gene discussed is IFNG; the disease is gestational diabetes.