Cancer has been seen in humans as one the most potentially fatal disease for thousands of years and only in the recent couple of hundred years have we discovered that most information necessary to bring us to today’s understanding and knowledge (Kenny 2007, Weinberg 1996) was achieved by extensive research of cells, DNA, and epidemiology studies. As we know, currently cancer is acknowledged as having over a hundred different diseases, and is known to be the result of mutations of the genes and almost similar DNA which are responsible for the amount of cell division and production (Kenny 2007). Restraint of cell growth modulators can be a direct lead and result of certain tumours being developed and subsequently allow these tumours to acquire the ability to attack and occupy the bloodstream and essentially be able to travel via the bloodstream to other parts and organs in human bodies which is known as metastasis (Loeb et Al 2003). Once this has occurred , the cancer is then categorized as malicious and becomes a dangerous and serious threat to the carrier (Weinberg 1996). In this essay I will describe and explain the process of this and how our genes mutate and lead to metastasis of cancer cells. Processes of exogenous and endogenous are likely to result in mutated genes leading towards cancer. (Schulz 2005, Knowles & Selby 2005). There are three known classifications of carcinogens, which are described to be cancer-causing agents based on the fact that they directly boost effects and thus cause mutations of the alterations already in place. The three classifications include: Chemical carcinogens which can be related to cigarettes and the mutations created as a result of the chemicals involved; Physical carcinogens which involves... ... middle of paper ... ...of not only them but also other things. (Schulz 2005). Finally, in conclusion, gene mutations and alterations affect the body’s ability to control the rate of cell division, which therefore defines cancer the direct result of gene mutation. Cells affected by mutations are exposed to the reproduction into a tumour. Once the tumour expands in growth, more and more mutations occur in subsequent cell divisions and eventually become a dysplasia and instigates invasion into surrounding tissues. In simpler terms, the cancer is spread to other organs and parts of the body. Following this, metastasis occurs resulting in the cancer spreading through the person and/or animals blood stream and/or lymphatic systems and forms other colonies which thus secretes other harmful organelles, and also disrupts normal bodily function, and possibly leading to and eventuating in death.