C4A and chronic kidney disease: Among these proteins, NFATC1, PFKFB2, SDCCAG8, YOD1, FGF5, C2CD2L, sRAGE, GCKR, DJC10, Apo A-IV, TCEA2, IGFBP-5, and C4a were colocalized with CKD (PPH4 > 0.8), while BTN3A2, INHBC, MFAP4, BTN3A3, GNPTG, and activin AC were moderately colocalized with CKD (PPH4 > 0.5) (Additional file 1: Fig. S8, Additional file 2: Table S8).