Cancer can result from expression of mutant forms of these proteins: growth factors (生長因子)(I), growth factor receptors (生長因子受體)(II), signal-transduction proteins (信息傳導蛋白)(III), transcription factors(轉錄因子) (IV), pro- or anti-apoptotic proteins(促進或抑製細胞凋亡蛋白) (V), cell cycle control proteins (細胞循環控製蛋白)(VI), and DNA repair proteins (DNA修複蛋白)(VII). Mutations changing the structure or expression of proteins in classes I–IV generally give rise to dominantly active oncogenes. The class VI proteins mainly act as tumor suppressors; mutations in the genes encoding these proteins act recessively to release cells from control and surveillance, greatly increasing the probability that the mutant cells will become tumor cells. Class VII mutations greatly increase the probability of mutations in the other classes. Virus-encoded proteins that activate growth-factor receptors (Ia) also can induce cancer.
The seven types of proteins that participate in controlling cell growth