TOP1 and malignant colon neoplasm: These studies have found high Top1 expression in 45% (n = 62) of metastatic CRC patients that received a first line 5 FU/CPT-11 chemotherapy (64), 86% (n = 29) of primary colon cancers (65), 31% (n = 13) among patients with recurrent CRC (66), 17% (n = 1,313) in metastatic CRC patients (67), and a study comprising 498 Dukes’ stage B and C patients reported positive/high Top1 protein expression in 48% of the cases (68).