CAR-T cell therapy, which received FDA approval in 2017, are highly effective against some blood-borne cancers and offer significant benefits but are not uniformly applicable to all forms of cancer. In addition, in patients with solid tumors, T cells can cause devastating and even fatal side effects. That’s why researchers at McMaster University have developed a promising new immunotherapy for solid tumors using genetically engineered “natural killer” (NK) cells that can distinguish between cancer cells and the healthy cells that are often mixed in and around tumors and destroy only the targeted cells. For their experiments, the researchers took “natural killer” cells from the blood of breast cancer patients. The researchers then genetically modified them to target specific receptors on the cancer cells. They have successfully tested the CAR-NK cells in the laboratory on tumor cells from breast cancer patients. The results are very interesting and there is good reason to believe that this technology would have a similar effect on solid tumors associated with lung, ovarian and other cancers. The next step in moving the therapy toward clinical use is to conduct human trials, which the researchers are in the process of organizing.