We aimed to investigate the effects of a 6-month HOET on interleukin (IL)−1 beta (IL-1ß), IL-2, IL-6, IL-10, IL-12p70, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), and the mGPS of colorectal, breast, and prostate cancer patients after surgery. The gene discussed is IFNG; the disease is prostate cancer.