The fecal gene SCD2 test is a non-invasive screening modality for colorectal cancer. For colorectal cancer, some researchers have found that the SDC2 gene undergoes changes in methylation levels at the stage of intestinal adenomas (early stage), and the specificity of the SCD2 gene is good and is not affected by drugs. There are intestinal exfoliated cells in the feces, and the use of exfoliated cells in the feces to detect the expression of the SCD2 gene can also reflect whether the colorectal mucosal cells have elevated expression of oncogenes. This is an emerging colorectal cancer screening method, because only need to collect feces is more convenient for patients, so it is a very good way of cancer screening, but the price is higher, the current application is less.