The expression of these three genes, similar to the results observed in cell culture, was significantly downregulated in both seminoma (n=8; APOLD1: P<0.005; PCDH10: P<0.05; RGAG1: P<0.001 by two-tailed Student's t-test) and embryonal carcinoma (n=9; APOLD1: P<0.005; PCDH10: P<0.05; RGAG1: P<0.0005 by two-tailed Student's t-test) and in a case of yolk-sac tumour (n=1) compared with normal testicular tissue (n=8) (Figure 3B). The gene discussed is RTL9; the disease is embryonal carcinoma.