## Cancer is a disease caused by uncontrolled cell division

The term cancer is used as a collective term for the entire group of cancers. The essence of cancer is uncontrolled cell division, where cells can divide faster, at the wrong time, in the wrong place, or despite damage. Tumour cells are our human cells, but due to a change in regulatory mechanisms, they no longer follow the instructions of the rest of the body. They become their own "organism" that behaves in a way that allows them to survive.

The cause of cancer is a failure of the mechanisms that control healthy cell division. It is called a solid tumour when the dividing cells begin to form solid and compact foci located in an organ, for example in the liver or brain. A second type of tumours are hematologic tumours, such as leukaemia, which do not form a solid foci of dividing cells. Although such tumour cells may temporarily clump together, they normally circulate in the blood and lymphatic system, which is why they are called liquid tumours.