To investigate whether olfactomedin 4 (OLFM4) is associated with ovary tumorigenesis, we examined its expression in normal ovary; serous cystadenoma; serous borderline tumor; and well-, moderately- and poorly-differentiated serous adenocarcinoma using immunohistochemistry (IHC). This evidence concerns the gene OLFM4 and serous adenocarcinoma.