Previous research demonstrating isochromosome 12p in both GCTs and HMs suggested that these malignancies had a common progenitor, and the identification of the same gene mutations, including of TP53 and PTEN, in both mGCTs and AML samples in two cases established the idea that the mGCT and AML share a founding clone [6, 9, 10]. This evidence concerns the gene PTEN and acute myeloid leukemia.