C18orf19 (chromosome 18 open reading frame 19) is a 272 amino acid single pass membrane protein containing one DUF1279 domain and is encoded by a gene located on human chromosome 18. Chromosome 18 houses over 300 protein-coding genes and contains nearly 76 million nucleotide bases. There are a variety of diseases associated with defects in chromosome 18-localized genes, some of which include Trisomy 18 (also known as Edwards syndrome), Niemann-Pick disease, hereditary hemorrhagic telangiectasia, erythropoietic protoporphyria and follicular lymphomas.