STAT2 and polymyositis: Another study reported that the breakdown of positive IFN-I signatures (top five IFIGs were IFI6, RSAD2, STAT2, IFI44, and IFI27) in whole blood of patients were 73% SLE, 68% SSc, 66% DM, 61% polymyositis (PM), and 33% RA [29].