system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are some body parts more likely to get cancer than others?
gpt
Cancer can develop during the process of cellular replication because a copy of *all* of the cell's DNA must be made for the new cell. During this process, mistakes can be made, resulting in DNA that accidentally codes for unregulated growth (resulting in a tumor).

Certain types of cells in the body replicate very often and are therefore more likely to develop cancer. Examples of this are the lining of your GI tract or the cells of the lung. 

Other types of cells, like those found in your muscles or bones, do not replicate very much at all and as a result are more rare.