How can uncontrolled cell division become a problem in the body?
( explain in a paragraph)

Over time, these cells become increasingly resistant to the controls that maintain normal tissue ... and both copies within a cell must be mutated in order foruncontrolled division to occur. ... barriers of the body so that they can both enter and exit the blood or lymph vessels. ... Translocation spells trouble for social species

 Cancer cells are cells gone wrong — in other words, they no longer respond to many of the signals that control cellular growth and death. Cancer cells originate within tissues and, as they grow and divide, they diverge ever further from normalcy. It can lead to a deadly cancer.

Except hold on to his or her beliefs even if there is no evidence for those beliefs.