 While genetically modified viruses with CRISPR editing have been successfully used as research tools in laboratories  or for gene therapy in clinical settings, all gene editing events are intended to physically occur within contained facilities.By contrast, HEGAAs for their intended mode of action relies on inducing gene editing events that occur largely or exclusively in the environment.Where HEGAAs are engineered to target obligate sexually reproducing species they can usefully be thought of being of two types