fChromosome 9 is one of the 23 pairs of chromosomes in humans. Humans normally have two copies of this chromosome, as they normally do with all chromosomes. Chromosome 9 spans about 150 million base pairs of nucleic acids (the building blocks of DNA) and represents between 4.0 and 4.5% of the total DNA in cells. These are some of the gene count estimates of human chromosome 9. Because researchers use different approaches to genome annotation, their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project (CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. Genes on human chromosome 9 The following is a partial list of genes on human chromosome 9. For a complete list, see the link in the infobox on the right.