Finally, a long-awaited breakthrough in cancer research: a new biological drug that successfully treats advanced skin cancer, by enabling the immune system to target and destroy cancer cells. Once the immune system kicks into gear, the tumor cells shrink and disappear, with minimal side effects.

The drug, Keytruda, was tested on 600 patients who had advanced melanoma, which had spread throughout their bodies. The results were so astonishing that the FDA moved to grant fast-track approval to this drug. In the study, 72% of patients responded to the drug, and 34% experienced significant improvement following use of the drug, with their tumors disappearing and not regrowing.

The key question for researchers was, why does the immune system not recognize and kill cancer cells in their earliest stages, before they spread and do damage to the body? They discovered that in the process of a tumor’s growth, it encounters a key checkpoint in the immune system—the PD1 protein—which acts as a “brake,” slowing down the immune system and preventing its activation. Researchers then found a molecule called pembrolizumab (trade name Keytruda) which targets PD1 and “lifts” the brake, allowing the immune system to attack the cancer. This approach is far superior to other chemotherapy drugs, which attack all growing cells and don’t differentiate between cancerous and healthy cells, leading to significant side effects.

A similar process, but on a cosmic level, will take place in the very near future. As of now, the forces of impurity—“kelipot”—that operate in this world owe their existence to the energy they draw from holiness. They are called kelipot, shells, because just like the peel of a fruit, they derive their energy only by close contact with the spirit of holiness. At this time, the kelipot manage to evade our defenses and prevent us from mounting an attack against them. We are confused and can’t tell the difference between good and evil, right and wrong, which enables the kelipot to flourish.

The close contact between good and evil, and the subsequent confusion, will end very soon, with the ultimate Redemption. According to the Zohar, since the sin of Adam and Eve we have been engaged in a process of birurim—refinement—selecting out the sparks of holiness from the kelipot. In recent years, the Lubavitcher Rebbe told us that the process of birurim has ended. We are approaching the time when “the spirit of impurity will be removed from this earth.” The kelipot will be left isolated, with no power of their own, and will disappear on their own accord. The result will be perfect physical and spiritual health for every individual and the world at large.