Getting big molecules into cells isn’t easy, and it isn’t easy on the cells, either. Bulk electroporation blows holes throughout the cell and can kill many of them. Viruses like AAV have limited capacity for macromolecules like Cas9, and lentivirus has safety issues. A new, gentler form of electroporation, called nanoEP, causes less trauma to cells and is more efficient, potentially boosting delivery of large molecules for gene editing or CAR T-cell immunotherapy.