TEX101, a member of the Ly-6/urokinase-type plasminogen activator receptor (LU)-family we previously identified, is a germ cell-marker glycoprotein. To date, it is reported that some members of the protein-family are overexpressed in a variety of cancer tissues. We previously reported Ly6k, a member of the LU-family, as an association molecule with TEX101 in murine male germ cells. LY6K (a human homologue of Ly6k) is overexpressed in head and neck squamous cell carcinomas (HNSCC). These facts led us to speculate that TEX101 may also exist in HNSCC, like LY6K. Using an anti-human TEX101 polyclonal antibody (pAb) established, we examined the expression of TEX101 protein in cancer tissues by immunohistochemical analysis. TEX101 was detected in the cancer cells of some tissue specimens from patients with HNSCC, whereas the normal squamous epithelium was immunonegative. The TEX101 protein was detected in cancer cells from 54 out of 64 (80.6%) patients with HNSCC. The rate of lymph nodes metastasis tends to be low in TEX101-positive patients, compared to patients with weakly positive and negative expression of TEX101. The present results imply that TEX101 is a novel cancer-related protein and may be useful as a marker for prognosis/diagnosis of HNSCC.