Fig. 4. ICB induces substantial infiltration of γδ T cells into MMR-d colon cancers with defects in antigen presentation.

a, The RNA expression of different immune marker gene sets in MMR-d B2M^WT (pink) and MMR-d B2M^MUT (red) cancers before (left) and after (right) neoadjuvant ICB in the NICHE study. The boxes, whiskers and dots indicate quartiles, 1.5 × IQR and individual data points, respectively. P values were calculated using two-sided Wilcoxon rank-sum tests comparing MMR-d B2M^WT versus MMR-d B2M^MUT cancers. b, The frequencies of γδ T cells, CD56⁺ NK cells, CD4⁺ T cells and CD8⁺ T cells in B2M^WT (n = 5) and B2M^MUT (n = 5) MMR-d colon cancers before and after ICB treatment. Data are median ± IQR, with individual samples (dots). P values were calculated using two-sided Wilcoxon rank-sum tests. c, Representative images of granzyme-B-positive γδ T cells infiltrating the tumour epithelium (white arrows) by IMC analysis of a B2M^MUT MMR-d colon cancer after ICB treatment. Scale bar, 50 μm.