For example, the complement factor cluster in HF cattle showed strong interactions between complement system proteins (C2, C3, C4A, CFB, CFH, C4BPA), LOC528040, MBL and TF in one cluster (Figure 4), whereas, in LF cattle, the complement cluster showed interactions between complement factors (CFB, CFH, C3, C4A, C4BPA, C8A, C8G), LOC528040 and SERPINA3-7 (Figure 5). The gene discussed is C2; the disease is hydrops fetalis.