On day 28 after medulloblastoma challenge, mice injected with IL-17 exhibited significantly smaller tumor sizes compared to the non-IL-17 treated mice (1966.81 ± 378.16 mm3 in IL-17-treated group vs 4468.18 ± 923.64 mm3 in the non-IL-17-treated group; P < 0.01). This evidence concerns the gene IL17A and medulloblastoma.