Caught in the antiviral crossfire: Ganciclovir-associated mutagenesis in HSC transplant recipients.

In this issue of Cell Stem Cell, de Kanter et al. (2021) show that most allogeneic hematopoietic stem cells do not acquire additional somatic mutations following transplantation. However, they observe somatic mutagenesis associated with the antiviral drug ganciclovir and find plausible evidence that it may contribute to some post-transplant malignancies.