Proteins refer to large and complex molecules that play numerous vital functions in the body. They are essential to the majority of the work done by cells and are necessary for the function, structure and regulation of the body's organs and tissues. A protein complex is a group of proteins, which interact with each other at the same time and place, and play a critical role in signaling cascades, regulatory processes, and cellular functions. They also play a significant role in biological systems and carry out a variety of functions such as signal transduction, DNA transcription and mRNA translation. Protein-protein interactions control the majority of cellular processes and abnormal protein-protein interactions can cause human diseases like cancer. This book unravels the recent studies on the systems analysis of protein complexes in cancer. It presents researches and studies performed by experts across the globe. This book is a vital tool for all researching and studying protein complexes and their relationship to cancer.