 Although DCC has been studied for many years, a significant amount of the data collected is contradictory and much of the focus has been on getting clear picture of the basics.When the genetic abnormalities that occur in advanced colorectal cancer were first identified, one of the most frequent events was found to be loss of heterozygosity (LOH) of region 18q21.One of the first genes sequenced in this region was "DCC", and it was subsequently analyzed for tumour suppressor activity.