Now, how exactly does a healthy cell become a cancer cell? Well, these carcinogens essentially affect the DNA molecules within our healthy cells. And when we develop a mutation in our DNA molecule we change the sequence of nucleotides on that DNA and that ultimately codes for different proteins and that can influence the functionality of the cell. Now, we develop a cancer cell when our abnormal cell essentially loses its ability to control the way that it divides. And that's exactly why cancer cells divide rapidly and uncontrollably and eventually form large, visible NASA we call tumors. And because these tumors are so large they can affect the way that our body functions and they can ultimately kill that organism, kill that individual.