In a cell, there are several parts of it that are there to stop this from happening. Cancerous cells do not have the genetic code to stop growing and reproducing. A regular cell will actually destroy itself it there is a mutation. If it does not get destroyed, it could potentially be tumorous, then it could eventually be cancerous.
I'm not sure but if you are talking about cells I think it is cytoplasm.
Cell Membrane
Hope this helps =]
