They found some important trends. Granulocytes from people over 50 years old had a reduced ability to kill cancer cells, as did granulocytes from people with cancer. This raises the possibility that cancer is not simply the result of getting too old, but a very specific weakening of the immune system.
The most important finding, however, was that the granulocytes' kung-fu grip declined dramatically during the winter months. Here's Dr. Cui:
Nobody seems to have any cancer-killing ability during the
winter months from November to April.