The need to suppress a patient's immune system after the transplantation of allogeneic cells is associated with wide-ranging side effects. We report the outcomes of transplantation of genetically modified allogeneic donor islet cells into a man with long-standing type 1 diabetes. We used clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 12b (Cas12b) editing and lentiviral transduction to genetically edit the cells to avoid rejection; the cells were then transplanted into the participant's forearm muscle. He did not receive any immunosuppressive drugs and, at 12 weeks after transplantation, showed no immune response against the gene-edited cells. C-peptide measurements showed stable and glucose-responsive insulin secretion. A total of four adverse events occurred, none of which were serious or related to the study drug. (Funded by the Leona M. and Harry B. Helmsley Charitable Trust; EudraCT number, 2023-507988-19-00; ClinicalTrials.gov number, NCT06239636.).

Cutaneous squamous-cell carcinoma (SCC) is primarily caused by oncogenesis mediated by ultraviolet radiation, and β-human papillomavirus (β-HPV) is believed to be a mere facilitator that is dispensable for the maintenance of cutaneous SCC. Here, we describe a woman with benign and malignant HPV-related diseases that include a recurrent, unresectable, invasive cutaneous SCC with β-HPV19 genomic integration in the context of germline pathogenic mutations in ZAP70, an adapter required for T-cell receptor (TCR) signal transduction. Restoration of the integrity of TCR signaling by allogeneic hematopoietic-cell transplantation led to the resolution of all HPV-related diseases, thereby revealing a direct role of β-HPV in skin carcinogenesis in hosts with defective adaptive T-cell responses. (Funded by the National Institutes of Health.).