In this study, the expression levels of CSC markers aldehyde dehydrogenase 1 (ALDH1) and ATP-binding cassette super-family G member 2 (ABCG2) were determined in Iraqi patients with colon cancer, and the association between the expression levels of these markers and tumor stages, lymph node involvement, patient's age and gender were examined. This evidence concerns the gene ABCG2 and neoplasm.