A subset of immune cells directly target colon cancers, rather than the immune system, giving the cells the aggressive properties of cancer stem cells, a new study finds. The researchers discovered that an epigenetic factor called DOT1L is regulated by IL-22, contributing to the cells developing stem cell properties. High levels of DOT1L in patient tumor samples were tied to shorter survival. The researchers suggest DOT1L may be a marker for colon cancer progression, and that this pathway could potentially be targeted in new colon cancer treatments.