As gene-editing technologies continue to improve, the field of cross-species organ transplants, or xenotransplantation, continues to grow. Shlomo Brody examines the approach of Jewish law toward the use of such technologies, particularly regarding the permissibility of implanting pig organs in humans.

Last month, doctors in Maryland completed the world’s first heart transplant using a heart that came from a genetically modified pig. This was a breakthrough because the donor pig had undergone gene editing to remove a specific type of sugar from its cells thought to be responsible for previous organ rejections in patients.

Pigs have been utilized [in such experiments] for a number of reasons: they are easy to breed and maintain (albeit with some environmental costs); they are available in wide numbers; they can be bred under pathogen-free conditions; and, most importantly, they are similar in anatomy and physiology to humans.

In the Bible, the pig is singled out because it has split hooves but does not chew its cud, thereby disqualifying it from being kosher food. “And the swine—although it has true hoofs, with the hoofs cleft through, it does not chew the cud: it is impure for you. You shall not eat of their flesh or touch their carcasses; they are impure for you” (Leviticus 11:7-8). Beyond the prohibition of eating pork, the sages also decreed that it is prohibited to raise pigs in Israel or around the world. Yet despite the prohibition of consuming pork as well as the general taboo around pigs, there was never a ritual prohibition against gaining benefit from pigs.

Early Friday morning, Israel attacked military installations near the Iranian cities of Isfahan and nearby Natanz, the latter being one of the hubs of the country’s nuclear program. Jerusalem is not taking credit for the attack, and none of the details are too certain, but it seems that the attack involved multiple drones, likely launched from within Iran, as well as one or more missiles fired from Syrian or Iraqi airspace. Strikes on Syrian radar systems shortly beforehand probably helped make the attack possible, and there were reportedly strikes on Iraq as well.

Iran itself is downplaying the attack, but the S-300 air-defense batteries in Isfahan appear to have been destroyed or damaged. This is a sophisticated Russian-made system positioned to protect the Natanz nuclear installation. In other words, Israel has demonstrated that Iran’s best technology can’t protect the country’s skies from the IDF. As Yossi Kuperwasser puts it, the attack, combined with the response to the assault on April 13,

clarified to the Iranians that whereas we [Israelis] are not as vulnerable as they thought, they are more vulnerable than they thought. They have difficulty hitting us, but we have no difficulty hitting them.

Nobody knows exactly how the operation was carried out. . . . It is good that a question mark hovers over . . . what exactly Israel did. Let’s keep them wondering. It is good for deniability and good for keeping the enemy uncertain.

The fact that we chose targets that were in the vicinity of a major nuclear facility but were linked to the Iranian missile and air forces was a good message. It communicated that we can reach other targets as well but, as we don’t want escalation, we chose targets nearby that were involved in the attack against Israel. I think it sends the message that if we want to, we can send a stronger message. Israel is not seeking escalation at the moment.