Cell division is tightly controlled by both positive and negative growth factors. Disruption of this balance leads to the onset of neoplasm (1 ). For example, a group of proteins, mostly encoded by oncogenes, act as positive factors to promote cell growth and proliferation. Tumor suppressor gene-encoding proteins, on the other hand, act as brakes to slow or stop cell growth and proliferation. Cancer is associated with activation of oncogenes and inactivation of tumor suppressor genes, which results in uncontrolled cellular proliferation and luck of adequate cell death.
