It is mainly the mutation of one, or both, out of two different genes that cause cancer - proto-oncogenes and tumour suppressor genes. We'll talk about them later in the A2 section.
As you already know, the cell cycle contains 4 phases, G1, S, G2 and mitosis.
- The most important phases are S (where DNA synthesis) and M (where the cell divides).
- The G in G1 and G2 means 'gap', but it might be better to remember them as 'growth' because that's what happens during these stages!