I'm using short-hand...I'm referring to radiation hormesis proponents (health physics deniers) as Hormies, much like others refer to Intelligent Design proponents (biology deniers) as IDiots.
One of the tired old claims of Hormies is that radiation stimulates the immune system. Hey, guess what? If I cut you or introduce a pathogen it will stimulate your immune system! That doesn't make cutting people or infecting them a good thing!
On top of that, chronic stimulation of the immune system (chronic inflammation) is associated with increased cancer risk. Silly Hormies.
A recent study shows how the gene TREM-1 can promote a chronic, low level state of inflammation and increase the cancer risk in mice. The link between chronic inflammation and cancer risk isn't new, this study just adds to the existing knowledge base.
(For more info on radiation effects on the immune system see my page "Radiation Stimulates The Immune System So LNT Is False", upper right).