IFNA2 and systemic lupus erythematosus: Finally, (1) TLR7-mediated IFN-α production was positively correlated with SLE disease activity, (2) TLR7-mediated IFN-α production was positively correlated with IFN-α concentration in serum and (3) IFN-α concentration in serum was positively correlated with SLE disease activity.