Another study by Young and colleagues,120 using a mouse model of colorectal carcinoma, showed that anti‐CTLA‐4 was highly effective when given before 20 Gy, citing depletion of Tregs by anti‐CTLA‐4; however, anti‐OX‐40 antibodies were most effective 1 day after radiotherapy, within the active antigen presentation period. The gene discussed is CTLA4; the disease is colorectal carcinoma.