Looking at the cell-specific IFN signature in more detail, LAMP3 (lysosomal-associated membrane protein 3) in the CD4+ T cells, CCL2 (chemokine [C-C motif] ligand 2) in the CD16− monocytes and SIGLEC1 (sialic acid binding Ig-like lectin 1) in both the CD16− and CD16+ monocytes were identified as potential cell-specific surrogate IFN markers for SLE and viral infection, whose increased absolute expression values were observed in autoimmunity. Here, CD4 is linked to systemic lupus erythematosus.