The abnormal behavior of all cancer cells regardless of cancer type is irregular cell signaling pathway activity. A mechanistic approach dealing with a fundamental and molecular view based signaling cascade are exciting and dynamic areas of cancer research. This book illuminates what we know, how we know and what remains to be discovered in this regard. The book explore and identify not only the key compounds of cell signaling pathway but also the interaction between them, the cross-talk. This book bring together up-to-date summaries of the signaling components that are likely to be used in diagnosis, prognosis and novel target for pharmaceutical intervention and therapeutic development and highlight the importance of molecular approach to clinical cancer research. A lot clinical trials and outcome are promising. The translation of recent advance in the knowledge of intracellular signaling into the generation of innovative molecular targeted cancer therapy are essential features of this book. Goals are manifold such as, resensitise chemoresistant target, capitalize on different mechanism of action and gain an advantage in the identification of best combination of drugs to induce clinically relevant response. The expert review compile in this book is an invaluable resource for graduate researcher and established scientist working in cell biology, pharmacy, experimental and molecular therapeutics and molecular medicine.