This study aimed to compare the difference in thromboembolism incidence between molecular-targeted agents in patients with unresectable advanced or recurrent colorectal cancer concurrently treated with a cytotoxic anticancer drug and VEGF or EGFR inhibitor, and to determine whether molecular-targeted drug administration or cancer has a greater impact on thromboembolism development. This evidence concerns the gene EGFR and Thromboembolism.