Immunoprecipitation of PTTG1 performed in samples derived from three frozen seminoma specimens (S1, S2, S3), obtained from the above-mentioned patients (P1–3), revealed that PTTG1 interacts specifically with ZEB1 in all samples analyzed, albeit to varying degrees, reflecting the inherent variability of human tumor tissues (Figure 5C). The gene discussed is PTTG1; the disease is seminoma.