Compound 22aa exhibited potent antiproliferative activity against both c-KIT wt-expressing GIST cancer cell line GIST-T1 (GI50 = 0.004 μM) and the c-KIT T670I-expressing GIST cancer cell line GIST-5R (GI50 = 0.026 μM). The gene discussed is KIT; the disease is gastrointestinal stromal tumor.