In a microarray analysis of purified monocytes heterozygous for the TLR1 SNP I602S, we identified genes that were differentially down-regulated in monocytes from active CD patients compared to monocytes from HC (53 genes in monocytes cultured with medium; 78 genes in monocytes cultured with Pam3CSK4 and 60 genes in monocytes cultured with FSL-1) (data not shown). Here, TLR1 is linked to Cowden disease.