Of genes that informed the cluster, IL1R1, IL6, IL6R and SERPINA3 expression was greater in the high inflammation schizophrenia and bipolar disorder subgroups compared to low inflammation subgroups (33–757%, all p < 0.05, Fig. 1B), except that SERPINA3 mRNA was not elevated in high inflammation bipolar disorder compared to low inflammation controls (p > 0.30). Here, IL6 is linked to bipolar disorder.