NFKB1 and bipolar disorder: Finally, duration of illness, which was available for 29 of the 35 bipolar disorder subjects in this study (Supplemental Table S1), was not correlated with expression levels of any NF-κB-related mRNA species (all r < |0.33|, all p > 0.08) with the exception of NF-κB2 (r = −0.38, p = 0.044).