The 2,3-diaryl isoquinolinone derivative 158 (Scheme 22A) was used as the hit compound since it exhibited significant VEGFR-2 activity (100.26% inhibition at 0.1 mg/mL) and potent cytotoxicity in breast cancer cell MCF-7 (IC50 value of 2.73 μM) [72]. The gene discussed is KDR; the disease is breast cancer.