CD109 is a cell surface protein, a member of the α2 macroglobulin/C3,C4,C5 family of thioester‐containing proteins. The authors have recently reported that high expression of the CD109 gene was detected in approximately half of the examined lung and esophageal squamous cell carcinomas as well as in the testis, and that CD109 has the characteristics of a cancer–testis antigen. In the present study CD109 expression in cervical squamous cell carcinoma was compared with that in endometrial adenocarcinoma by reverse transcription polymerase chain reaction (RT‐PCR). The result demonstrated that CD109 expression is significantly higher in cervical squamous cell carcinomas than in endometrial adenocarcinomas and normal cervix and endometrium. In contrast, when expression of RET finger protein (RFP) and bromodomain testis‐specific (BRDT) genes, which are also known to be highly expressed in the testis, was examined, no significant difference in their expression levels was observed between squamous cell carcinomas and adenocarcinomas. These findings suggest that CD109 may become a molecular target for the development of new therapeutics for squamous cell carcinoma of various tissue origins.