RELA and systemic lupus erythematosus: Interestingly, comparative network analysis of the phosphoproteomes of peripheral blood mononuclear cells of SLE patients versus healthy controls described PKCδ (beside Src kinases, the NF-kB signaling component RelA and HDAC1) as one of the genes with the most connections to other proteins in the altered network of SLE patients and therefore with significant role in the network stability [53].