plus Turkey Tail, Chaga and Lion's Mane mushrooms, burdock root, Essiac tea, and I'm sure there are others. Basically substances that help build up the immune system, rather than destroying it.
I have a kitty who's on much of this stuff since her surgery at Christmastime, and she's my longest living cancer cat after initial diagnosis... praying it continues, though she's almost 16. (I'm winging it on my own, since my vet thinks alternatives are hooey.)