Biology has made long strides recently; scientists have sequenced the human genome, and President Barack Obama has finally approved funding for stem cell research. Yet, another sector of molecular biology, gene therapy, remains a cloudy concept. Although it may appear promising, gene therapy is in reality a risky, unnatural technique that, taken to its extreme, poses severe ethical concerns. The Food and Drug Administration has not yet approved the procedure for sale, and for good reason: gene therapy is in its early stages, and society should not rush to approve or demand it without first considering all of its implications.

Gene therapy is a procedure to correct defective genes that are responsible for disease. A “normal” gene is inserted into the patient’s genome to replace an “abnormal” disease-causing gene using a carrier molecule, usually a genetically-modified virus.

If benevolent gene-carrying viruses seem too good to be true, that’s because they are. Gene therapy has not shown much success in clinical trials since the first attempt began in 1990. In 1999, gene therapy reached a low when 18-year-old Jesse Gelsinger died from multiple organ failure four days after starting his treatment. Other complications have arisen, and gene therapy’s success rate is at a low 12 percent. The primary reason for the adverse effects is the human immune response to the foreign gene, which can lead to organ shutdown. The viral vector may also induce toxicity, and even replicate within the patient, turning from savior to disease.

What we should fear above all in evaluating gene therapy, however, is not death from complications; rather, we should fear preventable death. Prospective patients must be wary of the overall infancy of the procedure in order to make the most informed decision. But with the general conviction towards science nowadays, this scenario is not always the case.

Consider the startling implications of gene therapy. In addition to unnecessary death, if approved without sufficient assessment and regulations, gene therapy has the potential to stretch widely-held morals thin. It is essentially the act of humans playing God—directly altering another person’s genes. What will we consider as a “disability,” and who will decide? Gene therapy’s best intentions could actually create a less tolerant society. Therapy can cost $100,000 in the first year—who will have access, and how will he afford it? What if people wish to use gene therapy to create intelligence, beauty or even custom-designed babies? More broadly, manufacturing “perfect” genes and injecting them into the population would create a more homogeneous gene pool, eliminating the advantages of a diverse genome. Clearly, we have too many issues to resolve before we can fully accept gene therapy today.

The National Institute of Health has spent $4 billion on gene therapy research since 1990, to no definite avail. But rather than ending all funding, research should continue, as there have been some successes. More importantly though, is that we should not rely on or hope for too much from gene therapy—at least not yet. We must fund the research of disease prevention and therapeutic treatments much more heavily than gene therapy. After all, the greatest progress in health in human history has been made in the discovery of preventive measures, such as in vaccination, sanitation and clean water and food. Mankind has dramatically improved its well-being in the last centuries without ever directly toying with genes. Thus, gene therapy should always be secondary to preventive measures, and never the go-to, de facto procedure.

Science is remarkable, but man is flawed. Gene therapy could eventually cure diseases, but we are impulsive—at times too desperate for solutions—and capable of moral shortcoming. We should not rashly endorse gene therapy, and potential patients must not impulsively order the treatment. Sherwin B. Nuland, a professor of surgery at Yale, wrote in his compelling essay, Narcissus Looks Into the Laboratory: “The kind of child our society resembles just now is one whose intelligence far exceeds his maturity…[We] should at least pause briefly to think about [science’s] motivations for plunging forward without the due consideration of the range of possibilities.” On the delicate edge of gene therapy, we need to strike a careful balance between putting faith in it prematurely and ending its research outright.