KMT2D KO potentiates the anti-tumor efficacy of ICIs by inducing DNA damage, augmenting mutational burden, enhancing IFN-γ-stimulated antigen presentation, and promoting infiltration of PD-1+ T cells and macrophages. Additionally, comparing anti-PD-1 treated mice with PBS treated mice, B2M KO was correlated with anti-PD-1 resistance. This evidence concerns the gene B2M and neoplasm.