  Procedures carried out to date involve the GM of somatic cells, but GM could potentially be applied to gametes or IVF embryos, resulting in the genetic changes being passed on to future generations: this is referred to as germ-line GM, or more recently (Rasko et al. 2006), “inheritable genetic modification.” Some bioethicists argue that the distinction between somatic cell and germ-line GM has moral significance, and that somatic cell interventions alone are permissible. A number of arguments are offered against germ-line GM: the long-term effects are uncertain; germ-line interventions are eugenic given that future generations are not patients; only existing persons can provide informed consent (Lappé 1991); humans have a basic right to be born with an unmodified genome (Mauron and Thevoz 1991); some modifications alter personal identity (Zohar 1991); and human trials face daunting ethical and practical challenges (Dresser 2004). Bioethicists who support germ-line GM counter these arguments with others: parents have reproductive autonomy (Zimmerman 1991); the fetus is being treated as a patient in prenatal surgeries, so why not the embryo (Nolan 1991); we constantly modify the conditions future generations inherit, and usually not with altruistic purposes (e.g., degraded environments) (Peters 1995); members of future generations would presumably consent to an augmentation of Rawlsian primary goods (Allhoff 2005); modifications could be reversed if harmful effects arise (Moseley 1991); the germ line might be the only or most effective level for intervention in some diseases (Munson and Davis 1992; Zimmerman 1991); germ-line interventions would avoid subsequent generations of a family having to undergo somatic cell GM or worry about carrier status (Munson and Davis 1992).