A core set of 67 type I IFN-associated genes is upregulated across leucocyte subsets (neutrophils, CD4 and CD8 positive T cells, monocytes) in SLE.24 Our panel contained probes targeting 17 of these genes and 13 of the 23 transcripts with higher expression were part of this core set, indicating that the type I IFN signature is a key molecular distinction between class V LN and MN. The gene discussed is CD8A; the disease is systemic lupus erythematosus.