GRN and viral myocarditis: Moreover, p-Janus kinases (JAK)2, p-STAT4, p-JAK3, and p-STAT3 were found to be decreased when purified mouse CD4+ T cells were co-incubated with progranulin, indicating that progranulin inhibits Th1 and Th17 cell differentiation via JAK/STAT pathway in viral myocarditis [72].