STAT3 and colorectal cancer: The protein Fad A of F. nucleatum binds to E-cadherin on colorectal cancer cells and induces β -catenin signaling, leading to regulation of inflammatory and oncogenic responses.18F. nucleatum regulates the polarization of macrophage to M2 phenotype by secreting IL-6 and activating IL-6/STAT3/c-MYC signaling.