Plasma levels of IL-27 were significantly raised in patients with carotid atherosclerosis (n = 140) as compared with healthy controls (n = 19) (median [interquartile range]: 4.77 [1.82–11.99] ng/mL versus 1.17 [0.85–1.80] ng/mL, p<0.001, Fig 1A). Here, IL27 is linked to carotid atherosclerosis.