Fusion protein amino acids 1659-1738 (cytoplasmic C-terminus) of rat NALCN (also known as Sodium leak channel non-selective protein, Four domain-type voltage-gated ion channel alpha-1 subunit, Voltage-gated channel-like protein 1, Vgcnl1, Nca and Cankon, accession number Q6Q760) Mouse: 98% identity (79/80 amino acids identical) Human: 95% identity (76/80 amino acids identical)