Plays an important role in innate and adaptive immunity by regulating nucleotide-sensing Toll-like receptor (TLR) signaling. Required for the transport of a subset of TLRs (including TLR3, TLR7 and TLR9) from the endoplasmic reticulum to endolysosomes where they can engage pathogen nucleotides and activate signaling cascades. May play a role in autoreactive B-cells removal. Interacts with TLR3, TLR5, TLR7, and TLR9 (probably via transmembrane domain). Relocalizes from endoplasmic reticulum to endosome and lysosome upon cell-stimulation with CpG dinucleotides (By similarity). Colocalizes with LAMP5 in large endosomal intracellular vesicles. Expressed in plasmocytoid dendritic cells (at protein level). Highly expressed in antigen-presenting cells. Expressed in heart, and at lower level in kidney. Expressed at low level in other tissues. Up-regulated by TLRs agonists. N-glycosylated. Disease susceptibility is associated with variants affecting the gene represented in this entry. Mutations in UNC93B1 resulting in autosomal recessive UNC93B1 deficiency predispose otherwise healthy individuals to isolated herpes simplex encephalitis due to impaired IFNs production. UNC93B1 deficiency, however, does not compromise immunity to most pathogens, unlike most known primary immunodeficiencies. Belongs to the unc-93 family. UNC93B1 mutation db