In resectable colon cancer, the NICHE study (99) enrolled 62 patients for treatment with neoadjuvant CTLA-4 and PD-1 blockade, and reported a 100% pathologic response rate (defined as > 50% tumour regression) in patients with mismatch-repair deficient (dMMR) disease. The gene discussed is CTLA4; the disease is malignant colon neoplasm.