3,3'-Diindolylmethane improves antitumor immune responses of PD-1 blockade via inhibiting myeloid-derived suppressor cells.

Overall, the strategy based on the combination treatment of anti-PD-1 antibody and DIM may provide a new approach for cancer immunotherapy. Cruciferae plants-rich diet which contains high amount of DIM precursor may be beneficial for cancer patients that undergo the anti-PD-1 treatment.