
In the present review, we accumulated the information on cancer, the second largest killer disease (the first being coronary heart disease) in the developed countries, and its prevalence in different regions of the world. Cancer is characterized by loss of control of cellular growth and development leads to excessive proliferation and spread of cells. This review mostly focused on the colorectal cancer, one of the most familiar cancers and cause of cancer death in developed countries. In India it has 6.3% out of an all 28 cancer reported. This review also revealed strongly the role of APC gene for the wide dispersal of colorectal cancer. APC gene is the most important gatekeeper of colonic epithelial cell proliferation and is responsible for controlling the onco protein called β-catenin. Microsatellite instability (MSI) occurs in 10−20% of colorectal cancers (CRC), and has been attributed to both MLH1 promoter hyper methylation and germ-line mutation in the mismatch repair (MMR) genes. It may support and paved the way for the therapeutic targets.