C9orf116 is a 136 amino acid protein that belongs to the UPF0691 family. Pierce 1 exists as two alternatively spliced isoforms, which are conserved in chimpanzee, dog, cow, mouse and rat. Pierce 1 is predominantly expressed in micrometastases and macrometastases of human small cell lung cancer. Pierce 1 is encoded by a gene that maps to chromosome 9, which consists of about 145 million bases, makes up 4% of the human genome and encodes nearly 900 genes. Notably, chromosome 9 encompasses the largest interferon family gene cluster. Considered to play a role in gender determination, deletion of the distal portion of 9p can lead to development of male to female sex reversal, the phenotype of a female with a male X,Y genotype. Hereditary hemorrhagic telangiectasia, which is characterized by harmful vascular defects, is associated with chromosome 9.