The evidence of CUX1 as a tumor suppressor first emerged from cytogenetic studies showing 7q− (deletions within the long arm of chromosome 7) in many types of cancers, including myeloid leukemia, pancreatic carcinoma, kidney carcinoma, colon carcinoma, ovarian carcinoma, lung carcinoma, head-and-neck carcinoma, cholangiocarcinoma, uterine leiomyoma, and breast cancer (81–88). Here, CUX1 is linked to breast cancer.