In clinical work, there are often family members of patients ask this question, which reflects that family members have more doubts about this. Tumor is not an infectious disease, so it will not be transmitted through contact or droplet, so the companions of tumor patients should not be worried about it. However, some tumors have family aggregation, which means there are certain genetic factors, such as some colon cancer, some breast cancer, etc. If two or more blood relatives are suffering from the same malignant disease, they should pay attention to go to hospital for physical examination. Some types of lung cancer can also have a genetic background, such as adenocarcinoma (especially the old classification of fine bronchoalveolar carcinoma), which has a clear genetic predisposition, especially among female relatives. So it should be noted.