Chromosome 4 spans more than 190 million base pairs (the building material of DNA) and represents between 6 and 6.5 percent of the total DNA in cells.

In a 2012 paper, 775 protein-encoding genes were identified on this chromosome.

[4] 211 (27.9%) of these coding sequences did not have any experimental evidence at the protein level, in 2012.

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.