A ki67 positive rate of 80-90% indicates that the tumor is highly active; survival needs to be judged according to the type and stage of the tumor, and cannot be judged only by the ki67 positive rate. Ki67, also known as proliferation index, indicates the “active degree” of the tumor, and this index can be used to monitor the condition of malignant tumors such as breast cancer, non-small cell lung cancer, colorectal cancer, etc. The increase of this index suggests that the tumor is metastatic or recurrent. Elevated proliferation index suggests that the possibility of tumor metastasis and recurrence will increase, but the prognosis needs to be judged in combination with other tumor indicators, pathological staging and other factors. Colorectal tumors often need to be combined with glycoantigen CA199, carcinoembryonic antigen CEA and other comprehensive judgment, a study pointed out that for CA199, CEA, Ki67, all three are elevated, the five-year survival rate of about 8.5%, while only a single positive indicator of the three, the five-year survival rate of 78.3%. What is also certain is that aggressive treatment improves prognosis. The presence of abnormally elevated ki67 positivity suggests prompt medical attention.