How did you know if the cell culture is cancer cell?

You might find this story interesting - the history of HeLa cells - a clone of malignant cells from a cancer patient who died 57 years ago in 1951. They still survive in laboratories. http://www.jhu.edu/jhumag/0400web/01.htm…

Cancer cells won’t stop dividing. They’ll pile up on one another and continue to grow as long as nutrients are available. That is a basic problem with cancers. The normal signals which tell cells to cease reproducing are not functioning normally. The checks and balances have been lost through mutations caused by a large number of instigating factors.