Through studies conducted prior to and in conjunction with this work (see companion article (Pitts et al., 2013), we identified additional markers associated with sensitivity to PF-309 in models of CRC and found that cells and tumors with an epithelial genotype (high CLDN2, CDH1, RAB25, CLDN3, CDH17) are more resistant and those with a mesenchymal genotype (high CALD1, VIM, ANK2, ZEB1) display sensitivity. The gene discussed is CLDN3; the disease is colorectal carcinoma.