Our data show that the ethyl acetate fraction from the branch of A. distichum (EAFAD-B) increased ATF3 expression and ATF3 knockdown by siRNA attenuated apoptosis by EAFAD-B, which indicates that ATF3 may be one of the molecular targets for anti-cancer activity of EAFAD-B in human colorectal cancer cells. This evidence concerns the gene ATF3 and colorectal cancer.