Lung cancer mrd test refers to the detection of tiny residual lesions after lung cancer has been treated. After radical treatment (e.g. complete surgical resection, radiotherapy, targeted therapy, etc.), the cancer lesions may not be completely eliminated, and the mrd technology can detect the residual malignant tumor cell load in the patient’s body. mrd test detects the ctDNA content by taking the patient’s peripheral blood, and the higher the content, the higher the risk of relapse. The results of mrd can help doctors to determine the amount of malignant tumor cells in the patient’s body, which is very helpful in determining the patient’s prognosis and the next step of the diagnosis and treatment plan. mrd is not only applicable to postoperative examination of lung cancer patients, but also applicable to other cancers.