IRF5 and systemic lupus erythematosus: Importantly, IRF5 has been previously shown to play an important role in the regulation of Th1 and Th17 responses, which are critical in driving SLE, and Irf5−/− mice are protected from multiple murine models of lupus, revealing defective T cell activation and global skewing towards Th2 [26,27,28,29,30,31,32].