While scientists have not arrived at a final number yet, as of 2014, estimates suggest that the number of protein-coding genes in the human genome could be as low as 19,000. Determining which genetic sequences are redundant or noncoding is arduous and complex, and there is still much disagreement.
A gene is a sequence of DNA base pairs that codes for a particular protein. These sequences account for only about 2 percent of the human genome. The rest is referred to as noncoding DNA, some of which serves various functions and some of which is apparently nonfunctional. The number of functional genes in the human genome is actually quite low, but the number of genes is not an indicator of the complexity of an organism, and many creatures have more genes than humans do.