Elevated plasma levels of IFN-γ were found in PD patients (Mount et al., 2007), and we recently identified altered transcriptional signatures in peripheral T cells of PD patients (Dhanwani et al., 2022) that may contribute to Th1/IFN-γ bias (Kustrimovic et al., 2018). The gene discussed is IFNG; the disease is Parkinson disease.