TP53 and glioblastoma: Colorectal cancers most likely carry hemizygous mutations, whereas we have already found that glioblastomas contain mostly heterozygous mutations of P53. Explanatory conditions for discrepancies between direct sequencing of the cDNA and the DNA analyses could be applied without any additional factors only for those cases presenting hemizygous mutations of P53. However, cases presenting the heterozygous mutation require searching for mechanisms responsible for selective overproduction of mutated P53 mRNA only.