What is cancer? Simply put, cancer is formed by abnormal proliferation of local tissues under the action of carcinogenic factors. Cancer cells are abnormally proliferating cells. The proliferation of normal cells is limited. Because the self-control mechanism is destroyed, cancer cells can proliferate endlessly.

The English word for Cancer is capital cancer, which also means cancer in the constellation. Why "cancer"

It also means "crab" That is to say, "cancer" is a kind of irregular, no obvious boundaries, like a crab, free from any constraints, arbitrary reproduction, can spread to the surrounding, whether it is hard as stone bone or tough as cowhide fascia, can be infringed and damaged by this so-called "cancer" of crabs.