Assignment task: What are the major types of cancers? Which type of cancer accounts for most of the new cases/year and deaths/year due to cancer? What are the 5 main steps in the path of cancer development that eventually lead to metastasis? In normal tissues, cell-cell contact generates an important signal input (so called "contact inhibition") that controls entry into the cell cycle. What happens to this regulation in tumors?. How does the study of CML support the hypothesis that cancer development is initiated by a single abnormal cell? Does the accumulation of mutations follow a pre-determined order during cancer development? What are the key pieces of evidence that tumor progression involves successive rounds of randomly inherited change followed by natural selection What are the properties of the cancer cells that contribute to cancerous growth? What change in cancer cells allows them to divide indefinitely?