IL18 and schizophrenia: All three modules associated with schizophrenia were also related to immune/ inflammation response and contained four interleukin receptor genes, IL1R1, IL4R, IL15RA and IL18R1. The genes IL1R1 and IL18R1 are receptors for IL1 and IL18, which are both pro-inflammatory cytokines that induce and maintain the inflammatory cascade.59, 60 Studies of IL1B serum levels have found consistent abnormalities in schizophrenia3 and the co-expression module, S_M16 was positively correlated with IL1B protein levels in the frontal cortex of these same individuals (Table 1).