CD8A and cancer: When we compared mean diurnal levels (mean of 06:00h-10:00h-14:00h) GH (p < 0.001) and CD16 (p < 0.01) levels were higher in cancer patients, whereas IGF1 (p < 0.001), CD8 (p = 0.03) and CD8bright (p = 0.001) levels were lower in cancer patients.