DMC1 and cancer: Heterozygous polymorphisms that are usually silent can be lost during HR and template switching, thereby supporting the emergence of cancer cell sustaining mutations.27, 47 The preferential use of the homologous chromosome by DMC1 during meiotic recombination may be preserved in GBM cells, leading to copy number neutral LOH and/or chromosomal duplications, thus increasing inter- and intra-tumoral heterogeneity.