The function of Ensembl gene identifier ENSG00000186795 (KCNK18, potassium two pore domain channel subfamily K member 18) is as follows. K(+) channel that conducts outward and inward rectifying currents at depolarized and hyperpolarized membrane potentials, respectively. The outward rectifying currents are voltage-dependent, coupled to K(+) electrochemical gradient across the membrane, whereas the inward currents can be induced in response to activation of Ca(2+)- mobilizing receptors (PubMed:12754259, PubMed:15562060, PubMed:20871611, PubMed:22355750, PubMed:26919430, PubMed:30573346). Homo- and heterodimerizes to form functional channels with distinct regulatory and gating properties. In trigeminal ganglia sensory neurons, the heterodimers of KCNK18/TRESK and KCNK2/TREK-1 or KCNK10/TREK-2 inhibit neuronal firing and neurogenic inflammation by stabilizing the resting membrane potential at K(+) equilibrium potential as well as by regulating the threshold of action potentials and the spike frequency (By similarity). In thymocytes, conducts K(+) currents upon T cell receptor (TCR) signaling leading to sustained Ca(2+) influx and NF-kappa-B activation, FOXP3 transcription and positive selection of regulatory T cell (Treg) progenitor subsets (PubMed:34702947). Appears to mediate the analgesics effects of hydroxy-alpha-sanshool, a metabolite naturally present in Schezuan pepper and other Xanthoxylum plants (By similarity). {ECO:0000250|UniProtKB:Q6VV64, ECO:0000269|PubMed:12754259, ECO:0000269|PubMed:15562060, ECO:0000269|PubMed:20871611, ECO:0000269|PubMed:22355750, ECO:0000269|PubMed:26919430, ECO:0000269|PubMed:30573346, ECO:0000269|PubMed:34702947}.