A recent spatially resolved single-cell study by Galeano et al. [109] demonstrated that intratumoral bacteria preferentially colonize immunosuppressive microniches within CRC and OSCC tumors, characterized by CD66b+ neutrophil accumulation, T-cell exclusion, and increased expression of immunosuppressive molecules, including programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4, and arginase 1. This evidence concerns the gene PDCD1 and colorectal carcinoma.