In the NICHE study assessing dual agent inhibitory checkpoint blockade (PD-1 and CTLA-4), tumour regression was observed in 100% of MSI tumours, with a major pathological response (MPR ≤ 10% residual viable tumour) rate of 95% and a pathological complete response (pCR) rate of 60% [55]. This evidence concerns the gene CTLA4 and neoplasm.