TLR2 and colorectal carcinoma: Of all the TLRs that are functional in humans, the single nucleotide polymorphisms (SNPs) of five TLR genes—TLR2, 3, 4, 5, and 9—have been reported to be involved in modulating the risk of CRC extensively [17, 21, 22, 25, 28, 49, 101, 102].