A cell is the structure which performs all the processes that are necessary to sustain life. Cells reproduce through a complex process called cell division. A cell can grow out of control and turn into a cancerous cell. These uncontrolled cells ignore signals to stop dividing, and spread to other areas of the body. This defect is due to several genetic changes in the cell. The gene mutations allow the abnormal cells to invade normal tissues. They then travel to other parts of the body through the bloodstream and continue to divide. This process is called metastasis. Cancer-producing viruses can also cause abnormal cell division. This book explores all the important aspects of biology of cancer in the present day scenario. It provides significant information about cancer cell biology to help develop a good understanding of the discipline and its related fields. With state-of-the-art inputs by acclaimed experts of this field, this book targets students and professionals.