OPCs and astrocytes are known to produce interleukin 33 in the brain (Zhang et al., 2014), and the performance of interleukin 33 knockout mice in the elevated plus maze and open field test is indicative of reduced anxiety (Dohi et al., 2017), suggesting that increased interleukin 33 release could conversely increase anxiety. The gene discussed is IL33; the disease is Anxiety.