WNT signaling pathway is implicated in carcinogenesis. Here, we cloned and characterized human WNT11, which showed three amino-acid substitutions (Ala121Thr, Gly156Arg, and Ser271Trp) compared with human WNT11 cDNA previously isolated by another group. WNT11 encoded a 354 amino-acid polypeptide with five N-glycosylation sites. Gly156 of human WNT11 was conserved in other members of the human WNT family, such as WNT2B1, WNT2B2, WNT3, WNT3A, WNT5B, WNT6, WNT7B, WNT8A, WNT10A, and WNT14. The Ala121-Gly156-Ser271 WNT11 allele isolated in this study was also identified in human genome draft sequence AC069055. Expression profile of WNT11 was next investigated. The 4.3-kb WNT11 mRNA was expressed in fetal lung, kidney, adult heart, liver, skeletal muscle, and pancreas. WNT11 mRNA was significantly up-regulated in a gastric cancer cell line MKN45 and a cervical cancer cell line SKG-IIIa. Among various types of human primary tumors, WNT11 mRNA was up-regulated in four cases of colorectal adenocarcinoma, and a case of renal cell carcinoma. Up-regulation of WNT11 mRNA might play an important role in human carcinogenesis through activation of the WNT signaling pathway.