TLR4 and breast cancer: In vivo and in vitro studies reveal that the surface adhesin Fap2 of F. nucleatum binds to elevated polysaccharide d‐galactose‐β (1‐3)‐N‐acetyl‐D‐galactosamine (Gal‐GalNAc) in BC tissues, enabling colonization and accelerating tumor progression, while F. nucleatum‐derived small EVs promote oncogenic behaviors in BC cells via TLR4‐dependent signaling [285, 286].