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There is estimated to be about 30 trillion (3×10¹³) human cells in the adult human body, varying from about 20 to 40 trillion depending on the sex, age and weight, and a roughly equal number of bacterial cells.^{[1][2][3][4][5][6]}(this have not yet been measured in its enterity emperically, but is based on smaller samples of emperical observation). The human cells have so far been categorized into over 500 cell types^[2] based on location and function within the body, there is usually a lot of variants of these types of cells depending on what surface proteins they have. We have about 1000 cells which have been given unique names listed here, based mostly on the HubMap database.

The main cellular components of the human body by count^[4]

	Cell type	% cell count
	Erythrocytes (red blood cells)	84.0
	Platelets	4.9
	Bone marrow cells	2.5
	Vascular endothelial cells	2.1
	Lymphocytes	1.5
	Hepatocytes	0.8
	Neurons and glia	0.6
	Bronchial endothelial cells	0.5
	Epidermal cells	0.5
	Respiratory interstitial cells	0.5
	Adipocytes (fat cells)	0.2
	Dermal fibroblasts	0.1
	Muscle cells	0.001
	Other cells	2.0

in 1996 scientists revealed a 'map' of 16000 human genes.^[7] Leading to estimates that humans likely had around 100 000 genes^[8] (or regions that code for human proteins). However actual sequencing did not start before around 1999, and it wasn’t until 2003^[9] that the first complete draft of a human genome revealed that there was roughly 20000-25000, as most DNA does not code for any protein but rather serve other more administrative functions or leftovers from the past. It is difficult to say that we have not made similar mistakes when estimating how many cells we have as there are still substantial gabs in our understanding of human cells.

Major efforts to map all human cells

Several efforts have been made to make a list or a map of all human cells.^[10][11][12] One of the largest and most recent is the HuBMAP (Human BioMolecular Atlas Program).^[13] They managed to organize 1551 samples across 17 collections. However, this project still only mapped about 31 of the human bodies' 70 organs. Their datasets and visualisations place great emphasis on biomarkers and location in the body, but less on cell development and how cells can change over time. Usually specific surface proteins are used to identify cells, and based on this they are put into different categories. Another major effort to make an overview of these proteins that allows us to observe cell types is the Swedish Protein Atlas.^[14]

The Human Brain Project has attempted to map the human brain,^[15][16] although much of the publicly accessible model does not have cellular resolution.

Standards and naming conventions

So far not all cells which can be found in the human body have been documented. There is no good way to make the experiment where you check if all celltypes identified so far could be taken from an measured in a single donor. Proving that the cells types are universal to all humans. This is partly due to a lack of standards, as we are still not entirely sure what we would need to measure, in order to capture every cell type which can be found.

A good few attempts have been made and is beeing made, for creating standards for identifying cells consistently,^[17] as well as for how to work with especially STEM cells.^[18] However there is still no standard which are used industry wide, nor any defintions which have been accepted by the wider scientific community. Often making it difficult to say weather some collected and observed cells are really one or multiple types of cells. This lack of standards makes it difficult to estimate how many cell types and how many of each cell types can be found in the human body, as well as difficult to predict which young cells you would need to develop with mature cells. The list on this wikipedia article also suffers to some inconsitencies due to multiple sources using different conventions.

Complete lists of human cells known so far