Chromosome 9 spans about 138 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).

So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes.

[4] The following is a partial list of genes on human chromosome 9.