When the aPL subjects were segregated and compared based on both thrombosis and SLE status, it revealed that the NTS group without thrombosis and SLE had the highest mean GCNs for total C4 and C4A (3.78 and 2.12, respectively), but the lowest C4B mean GCN (1.66). Here, C4A is linked to systemic lupus erythematosus.