The known indications for erlotinib, whose target genes are ABCG2 and EGFR, are colon cancer, glioma, head and neck cancer, etc. Similarly, the known indication for olaparib, whose target genes are PARP1 and PARP2, is ovarian cancer (Fig. 5a). This evidence concerns the gene ABCG2 and malignant colon neoplasm.