Immunomodulatory and anti-tumorigenesis functions against CRCs have also been reported, especially the activation of toll-like receptor 2 (TLR2)/nucleotide-binding oligomerization domain-leucine rich repeats-containing receptor 3 (NLRP3)-mediated M1 tumor-associated macrophages, inhibiting tryptophan metabolism through the AhR/β-catenin signaling pathway (Fan et al. 2021b; Zhang et al. 2023). This evidence concerns the gene TLR2 and neoplasm.