The function of PANX1 (pannexin 1, Ensembl gene identifier ENSG00000110218) is as follows. Ion channel involved in a variety of physiological functions such as blood pressure regulation, apoptotic cell clearance and oogenesis (PubMed:15304325, PubMed:16908669, PubMed:20829356, PubMed:20944749, PubMed:30918116). Forms anion-selective channels with relatively low conductance and an order of permeabilities: nitrate>iodide>chlroride>>aspartate=glutamate=gluconate (By similarity). Can release ATP upon activation through phosphorylation or cleavage at C-terminus (PubMed:32238926). May play a role as a Ca(2+)- leak channel to regulate ER Ca(2+) homeostasis (PubMed:16908669). {ECO:0000250|UniProtKB:Q9JIP4, ECO:0000269|PubMed:15304325, ECO:0000269|PubMed:16908669, ECO:0000269|PubMed:20944749, ECO:0000269|PubMed:32238926}. [Caspase-activated pannexin-1]: During apoptosis, the C terminal tail is cleaved by caspases, which opens the main pore acting as a large-pore ATP efflux channel with a broad distribution, which allows the regulated release of molecules and ions smaller than 1 kDa, such as nucleotides ATP and UTP, and selective plasma membrane permeability to attract phagocytes that engulf the dying cells. {ECO:0000269|PubMed:20944749, ECO:0000269|PubMed:32238926, ECO:0000269|PubMed:32494015}.