Question: Normally, when cells in the human body come in contact with one another, they stop dividing, a phenomenon called contact inhibition. Cells that do not stop dividing when in contact with other cells are considered cancerous. What specific structures do you think might not be working in cancer cells?

Remsha Afzal answered on 14 Nov 2018:

Great question! And I see you’ve done your research 😀 So cancer cells don’t have the ability to stop dividing because either their cell cycle proteins are in overdrive, or the proteins responsible for telling a cell to stop dividing are mutated so they don’t have that brake in the cell cycle. Two of the most common genes mutated in cancer cells (called proto-oncogenes) are called c-Myc and Ras. And the most important ‘brake’ protein (that tells the cells to have a break and not divide anymore is called p53. These proteins are all abnormal or mutated in cancer cells. There are other ways to make a cell cancerous too, like manipulating some other cell cycle regulating genes.