ABCG2 and colorectal cancer: Multiple bioinformatical and biostatistical analyses were conducted, including screening of ABCG2 expression in a collection of various malignancies, comparing ABCG2 expression in normal and malignant colon and rectum tissues, evaluating the relationship between the ABCG2 expression level and clinical features of CRC and prognosis in colorectal cancer, and constructing the functional network of the ABCG2 protein.