Genotyping of microsatellites, single nucleotide polymorphisms (SNPs) and major histocompatibility complex (MHC) alleles as well as mitochondrial DNA sequencing have supported this theory of allogenic transmission, demonstrating that tumour genotypes did not match those of the their host and genotypes of tumours from different individuals were identical or near identical to each other3, 14–16. The gene discussed is HLA-C; the disease is neoplasm.