In colorectal cancer, the rate of TOP1 CNG has been reported to range from 53 to 84% [26, 27]; moreover, in a metastatic setting, a borderline significant association (p = 0.007) between an increase in the TOP1 CN and an objective response to second-line treatment with irinotecan monotherapy has been reported [28]. Here, TOP1 is linked to colorectal cancer.