Intensive research is being carried out to enable the transplantation of organs from specially bred pigs to humans. However, the pig genome contains the genomes of various endogenous retroviruses (PERV-A, B and C) that could potentially cause infectious diseases. A research team at the Paul-Ehrlich-Institut has demonstrated in the Yucatan miniature pig breed (haplotype SLA D/D) that the retrovirus PERV-C could be reproductive and therefore infectious. The identification of the PERV-C genome now makes it possible to remove the PERV-C retrovirus genome from the pigs‘ genome via gene editing (Journal of Virology, 8 March 2023).