TP53 and cancer: For the purpose of regenerative medicine, where safety should be considered, polyploid cells have been knowingly transplanted into humans without apparent ill effect (Nelson et al., 2002), and while we feel that most groups would agree that a cell line carrying a TP53 mutation conferring a lifetime cancer risk of nearly 100% should not be transplanted into patients if a suitable alternative exists, other variants should be considered on a case-by-case basis depending on research needs.