Colorectal cancer is a major killer as the cases are increasing worldwide. The researches and studies in this field would be helpful to provide some efficient therapeutic measures for colorectal cancer. This book presents some basic steps being taken in order to understand and diagnose this disease. This book discusses the analysis done by scientists on the data and evidences available related to genes, infections related to colorectal cancer and other factors. A study of cell and molecular biology, examining the tumor microenvironment and the role of intestinal microbes and host-microbial interactions has been described in the book. This text is a valuable account of information for scientists, researchers and medical professionals engaged in this field.