The truth is: people living in the same area or in the same family are more likely to suffer from cancer or tend to suffer from the same kind of cancer. Cancer seems to have the suspicion of being “contagious”, but in fact, the so-called “contagion” of cancer is only caused by the same or similar environments, that is to say, they live in the same or similar cancer-causing environments. However, the so-called cancer “contagion” is only caused by the same or similar environment, that is, they live in the same or similar cancer-causing environment, the same area has similar lifestyle or undergoes the same environmental pollution; husband and wife have highly similar lifestyles and habits. These poor lifestyles or habits or environmental pollution are important factors that lead to the development of cancer. It is not that cancer is contagious, but that they are exposed to the same or similar cancer-causing environments, which results in a relatively concentrated incidence of cancer. Therefore, please remember that if your family members or close friends have cancer, please spend more time with them, do not discriminate against them, give them more care and attention, do not avoid them, do not rub salt into their wounds, and do not bring them double physical and mental harm.