PBRM1/Pbrm1 deficiency in colorectal cancer promoted PD-1 immunotherapy sensitivity and chemotaxis of CD8+ T and NK cells in the microenvironment in vivo and in vitro. ATAC sequencing revealed that deletion of Pbrm1, a critical component of the SWI/SNF complex, increased chromosomal accessibility in tumor cells and triggered the release of cytokines, such as CCL5 and CXCL10, by activating the NF-κB signaling pathway. Here, CD8A is linked to colorectal cancer.