Non-alpha subunit of nicotinic acetylcholine receptor (nAChR). Involved in nAChR sensitivity to nicotine and levasimole. Interacts with lev-1 (PubMed:15990870). Component of nicotinic acetylcholine receptor composed of 2 non-alpha subunits lev-1 and unc-29, and 3 alpha subunits unc-38, unc-63 and lev-8 (PubMed:15990870). Interacts with oig-4 (PubMed:21252855). Interacts with crld-1 (PubMed:30407909). Co-localizes with unc-38 and lev-1 at nerve cord synapses. RNAi-mediated knockdown causes a resistance to nicotine-mediated paralysis and small impairment in mobility. Belongs to the ligand-gated ion channel (TC 1.A.9) family. Acetylcholine receptor (TC 1.A.9.1) subfamily.