GSK2126458 induced morphologic changes in four tumors (two invasive ductal carcinomas, one invasive lobular carcinoma, and one ovarian dysgerminoma), intracellular caspase-3 activity in three tumors (two invasive ductal carcinomas and one poorly differentiated signet ring adenocarcinoma of gastric origin), and immunohistochemical evidence of apoptosis in at least four tumors (three invasive ductal carcinomas and one adenocarcinoma of gastric origin). This evidence concerns the gene CASP3 and invasive ductal breast carcinoma.