IL17A and systemic lupus erythematosus: Considering previous evidence, the present study aims to evaluate the role of type I IFN signalling in the upregulation of BLyS in SLE patients by analysing the expression of BLyS and IFNRA1 (the α-chain of the common receptor for type-I IFNs) on the membrane of different leukocyte populations, as well as their possible association with the IL-17 production and the serum levels of other relevant pathogenic cytokines.