IL6 and major depressive disorder: A study measuring interleukin-6 (IL-6) levels and relative diurnal cortisol variation in depressed cancer patients revealed that IL-6 levels are increased by a factor of seven (18.7 pg/ml vs. 2.7 pg/ml), whilst relative diurnal cortisol variation is decreased by a factor of six (11.7% vs. 60.6%) among cancer patients with depression compared with those without depression.