COX4NB, or ER membrane protein complex subunit 8, is a human gene encoded by EMC8. It may also be known as: Neighbor of COX4; Protein FAM158B; family with sequence similarity 158, member B; C16orf2; C16orf4; FAM158B. The encoded protein has an amino acid length of 210 and a mass of 23.8 kDa. COX4NB is a member of the EMC8/EMC9 family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog.