IL18 and hereditary elliptocytosis: In addition to ammonia, the levels of a number of metabolites may be increased or altered in the blood of patients with HE, including αKG, αKGM, Gln, Glu, cyclic guanosine monophosphate (cGMP), interleukins-6 and -18 (IL-6, IL-18), and 3-nitrotyrosine, which has previously been positioned as a possible marker for the diagnosis of HE [10,12,15,16].