Using CNDO-109-NK cells in high risk AML patients showed no toxicities even at highest administered dose [24] Regarding increasing the number of alloreactive NK cells infused followed by IL-2 injection, out of the 16 patients, 10 cases had fever for unknown cause, 4 cases showed bacterial infections where 2 developed pneumonia and the other 2 developed sepsis, only 1 patient died due to bacterial pneumonia but others recovered successfully. This evidence concerns the gene IL2 and bacterial infectious disease.