IL18 and angina pectoris: Polymorphic variants of the IL-18 receptor have been associated with an increased risk of MI [36]; circulating levels of IL-18 are increased in patients with unstable angina and levels were shown to correlate with the number of diseased arteries in women [37] and with increasing disease severity score [38], though no significant difference in IL-18 levels was seen between subgroups comparing CAD and non-CAD controls [36,37,38].