CLEC4C and systemic lupus erythematosus: Other monoclonal antibodies targeting IFN-α, such as sifalimumab and rontalizumab, showed suppression of ISG signatures and early clinical signals in SLE but were discontinued before late phase development [188,189].Upstream modulation of IFN production is represented by litifilimab (BIIB059), a monoclonal antibody against BDCA2 on plasmacytoid dendritic cells, which lowers IFN-I production and showed clinical benefits in cutaneous lupus erythematosus during the Phase 2 LILAC trial [190]; Phase 3 trials are ongoing in SLE and CLE.