Increased copy number of the PRDM14 gene has been reported in GCTs51 and a recent GWAS study identified PRDM14 as a susceptibility locus in testicular cancer.52 Studies in normal ES cells (where PRDM14 is also expressed but at much lower levels than in PGCs) provide evidence for a role in the progression of GCTs towards the YST phenotype. This evidence concerns the gene PRDM14 and testicular cancer.