The Human Genome Project has revealed that there are probably about 20,000-25,000 'haploid' protein coding genes. The completed human sequence can now identify their locations. read more
In addition, about 26% of the human genome is introns. Aside from genes (exons and introns) and known regulatory sequences (8–20%), the human genome contains regions of noncoding DNA. The exact amount of noncoding DNA that plays a role in cell physiology has been hotly debated. read more