For example, except for the common disease gene JAG1 between Tetralogy of Fallot and Alagille syndrome, the two diseases interact through 5 PPIs with a p value < < 0.01 in the network, including JAG1 – NOTCH1, JAG1 – NOTCH2, JAG1 – NOTCH3, DLL1 - NOTCH2 and DLL1 – NOTCH3. The gene discussed is NOTCH2; the disease is Alagille syndrome.