More than 50 new diaminoquinazoline derivatives have been synthesized and evaluated in a colon carcinoma cell growth inhibition assay using HCT116 and SW480 cells. Twenty compounds with good cell growth inhibitory activities (< 4 μM) were tested as inhibitors of the β-catenin/T cell transcription factor 4 (Tcf4) signaling pathway using a HCT116 cell- based luciferase reporter assay. Results from the biological activities as well as the ...