NR1D1 and Cluster headache: Furthermore, a microarray study that carried out whole transcriptome analysis in lymphoblastoid cell lines from 8 cluster headache and 10 bipolar disorder lithium responder patients found that two genes involved in the circadian system [RNA binding motif protein 3 (RBM3), and nuclear receptor subfamily 1, group D, member 1 (NR1D1)], were significantly dysregulated in both cluster headache and bipolar disorder patients when compared to controls (Costa et al., 2015).