Additionally, the treatment of mice in various models of melanoma, kidney and colorectal cancer using stereotactic irradiation (10 Gy) increased frequencies of Tregs in all models, with highly suppressive phenotypes characterised by higher expression of helios, CTLA‐4 and 4‐1BB expression in irradiated mice than non‐irradiated mice. This evidence concerns the gene CTLA4 and melanoma.