C4A and lupus nephritis: For example, several cytokines, such as CXCL13, CCL8, and TNF, which relate to B-cell and lymphoid structure biology, monocyte/macrophage recruitment, and classical pro-inflammatory cytokine signaling, diagnostic auto-antibodies, such as anti-SSA, anti-dsDNA, and anti-C4, as well as disease activity and urinalysis abnormalities consistent with lupus nephritis, strongly segregate individuals, being significantly associated to patient clusters across approaches.