TLR9 and Cowden disease: The single-nucleotide polymorphisms (SNPs) -1237T/C and 2848A/G in the TLR9 gene were recently linked to CD-associated variants in CARD15, IL23R, and DLG5, thus differentially modulating CD susceptibility.146 It remains to be shown whether these SNPs may functionally impair TLR9 sensing of commensal DNA, leading to aggravation of inflammatory disease through Treg/Teff imbalance in the intestinal mucosa.147