Studies on hypermethylated DNA in stool of CRC patients have been conducted using single gene hypermethylation markers. The gene primarily analysed has been hypermethylated VIM which also has a commercially available kit for stool analysis. The focus in the stool studies has been DNA hypermethylation as a screening marker for CRC. One study combined the iFOBT test with hypermethylation of the PHACTR3 gene, extracted from the iFOBT fluid. A positive result in at least one of the two tests raised sensitivity to 95% (19/20) at high specificity of 94% (45/48) for CRC and advanced adenomas.