As seen for adult seminomas (Korkola et al., 2006), paediatric seminomas were enriched for genes associated with pluripotency and the undifferentiated state [e.g. NANOG, POU5F1 (OCT3/4), TFAP2C and UTF] and paediatric YSTs were associated with genes such as AFP, those involved in differentiation (KRT8, KRT19), lipid metabolism (APOA1, APOA2) and proliferation pathways (Palmer et al., 2008). The gene discussed is POU5F1; the disease is seminoma.