List of human cell types

Cells may be classified[1] by their physiological function, histology (microscopic anatomy),[2] lineage, or gene expression.

[3][4][5][6][7][8][9] It is generally assumed that these cells share features with each other and thus may be organized as belonging to a smaller number of types.

[12] There is, for example, significant variation in these cell types depending on the specific surface proteins they possess.

However, actual sequencing did not start before around 1999, and it was not until 2003[17] that the first complete draft of a human genome revealed that there was roughly 20000-25000 protein-coding genes, as most DNA does not code for any protein.

[citation needed] Several efforts have been made to make a list or a map of all human cells.

This is partly due to a lack of standards, as scientists are still not entirely sure what is needed to measure, in order to capture every cell type which can be found.

[citation needed] The endodermal cells primarily generate the lining and glands of the digestive tube.

A neuron consists of a cell body with a nucleus and cytoplasm, from which long thin hair-like parts arise.