SPP1 and Cowden disease: In 7 out of 8 OPN/SPP1 SNPs forming the haplotype rs2728127-rs2853744-rs11730582-rs11439060-rs28357094-rs112661-rs1126772-rs9138, which was strongly associated with CD susceptibility, the IL-22 serum levels were nominally lower in CD carriers of the minor allele than in homozygous wildtype carriers, although these differences were for each SNP only small and statistically not significant.