Upon closer inspection, we detected in the xenografted area small nests of cells, which display downregulation of seminoma and pluripotency markers (SOX17, TFAP2C, OCT3/4) and upregulation of differentiation markers (AFP, EOMES, FOXA2, HAND1, ALB, CDX1, APOA1/A2/B/C1/E/H/M, FGA/B/H/L1, HPX, FLRT3, etc.)[9,10,11,12]. The gene discussed is TFAP2C; the disease is seminoma.