TIGIT and neoplasm: One of these autotransporter proteins in Fusobacterium nucleatum, Fap2 protein, is known to provide protection to CRC cells by restraining the immune response, such as NK cell cytotoxicity, tumor-infiltrating lymphocytes, and a T-cell attack [264], by interacting with the T-cell immunoglobulin and ITIM (TIGIT) receptor domain [264,265] thus promoting tumor progression.