Cancer and their tumors create and thrive in a microenvironment that is highly immune suppressant. By targeting specific genes and genetically modifying natural killer (NK) cells, the clinical outcomes of cancer immunotherapy have the advanced ability to overcome these diseases. NK cells in solid tumors have been reported to exhibit an inactive and dysfunctional state, and expanded NK cells under hypoxic conditions showed a decrease in cytotoxic ability. Drs. Dean Lee and Marcelo Pereira found that by using the developed approach that focuses on Cas9/RNP, the HIF1a in NK cells can permanently overcome the effects of hypoxia without the noted disadvantages of small-molecule inhibitors.