The absence of a mutation in a gene generally does not indicate whether or not it is cancer. Gene mutation and cancer are two different concepts. Cancer occurs when the cells of the body undergo a variety of genetic changes under the long-term interaction of various cancer-causing factors and gradually undergo excessive and abnormal proliferation. Cancer is not equivalent to genetic mutation. Therefore, a gene mutation does not necessarily lead to cancer, and cancer does not occur in all genes that are mutated. Cancer patients are often tested genetically to determine if they can be treated with targeted drugs. For example, EGFR gene mutation, which is a relatively common gene mutation in lung cancer, can be treated with corresponding targeted drugs, such as gefitinib, afatinib, daclatinib, ositinib, and amitinib, which can effectively control the disease process. And the fact that the gene does not show mutation generally only indicates that it is not suitable to apply the corresponding targeted drugs, but it does not indicate that there is no cancer. It is recommended to go to regular hospitals in time to do relevant examinations and make a clear diagnosis, so as not to cause delays in the condition.