Chromosome 22 Open Reading Frame 9 (C22orf9)

C22orf9 Evidence at protein level. Chromosome 22 is one of the 23 pairs of chromosomes in human cells. Humans normally have two copies of Chromosome 22 in each cell. Chromosome 22 is the second smallest human chromosome, spanning about 49 million DNA base pairs and representing between 1.5 and 2 % of the total DNA in cells.In 1999, researchers working on the Human Genome Project announced they had determined the sequence of base pairs that make up this chromosome. Chromosome 22 was the first human chromosome to be fully sequenced.Identifying genes on each chromosome is an active area of genetic research. Because researchers use different approaches to predict the number of genes on each chromosome, the estimated number of genes varies.