The Granulocytes do exist in humans but to varying effectiveness. A cure for cancer would seem to require finding a way to provide full anti-cancer strength granulocytes cells to all people who need it to fight cancer.
In 2003, Dr. Zheng Cui and his colleagues at the Comprehensive Cancer Center of Wake Forest University reported the discovery of mice with immune cells that rendered them invulnerable to cancer
Dr. Cui went on to show that it could resist multiple rounds of such injections, and were so impressed that they used him to father a whole colony of mice, all of whom shared this remarkable invulnerability to cancer. Based on that ability, he calls them spontaneous regression/complete resistance (SR/CR) mice.
In 2006, Dr. Cui electrified the world when he showed that the new strain's cancer-fighting abilities were caused by a particular subset of their immune cells -- members of a class of white blood cell known as neutrophil granulocytes.
Dr. Cui tested the ability of these cells to fight off cancer by transfusing them into normal mice with cancers. Surprisingly, the simple transfusion of the cancer-fighting immune cells from the resistant mice effectively transfered the same remarkable protection to the normal mice. And even more excitingly, the treatment didn't just prevent cancers from forming, but actually fought off existing cancer: when researchers transfused the anti-cancer white blood cells into normal mice with existing skin tumors, the tumors regressed completely in a matter of weeks. Moreover, a single dose of the cancer-fighting immune cells gave the normal animals a cancer immunity that often lasted for the rest of their lives.
Dr. Cui's team first went looking for the existence of potent cancer-killing granulocytes in a group of healthy volunteers. This was done by testing the volunteers' granulocytes' ability to destroy cancer cells in a petrie dish. They found that, unlike in mice (who seem to have an all-or-nothing effect), there appears to be a classical bell-shaped distribution of cancer-killing ability in the granulocytes of people in the population: a few people have white blood cells extremely weak cancer-killing activity, the great majority have an 'average' competence, and a very small group of outliers have the kind of overwhelming search-and-destroy activity (at least in a test tube!) that is seen in the SR/CR mice.
Surprisingly, they found that the ability of peoples' granulocytes to kill cancer is very sensitive to the season, stress levels and age.
Based on these promising findings, Dr. Cui applied to test the transfusion of granulocytes from highly cancer-resistant people into people with existing cancer -- a potential therapy he calls "GIFT" (for "Granulocyte InFusion Therapy"). He now has approval from both the IRB and FDA to move ahead with the trial, and the next step is to raise the necessary funding.