Syndecan-4 is highly expressed in seminoma cell line JKT-1 (relative fluorescence median ± SE, 4.64 ± 0.26), whereas statistically significant lower expression was detected in teratocarcinoma cell line NCCIT (relative fluorescence median ± SE, 2.90 ± 0.31) and embryonal carcinoma cell line NTERA-2 (relative fluorescence median ± SE, 2.2 ± 0.19). This evidence concerns the gene SDC4 and teratocarcinoma.