Human Cell Type Genes was one my first blog post. In that 16 October 2020 blog post I presented the “traditional histology cells”. It is a useful hyperlink of cells. Today however, I present the “question”.
Question: How many cell types does the human body have?
Answer: It depends on classification methods.
#1. Traditional histology: exactly 211 cell types.
#2. Recent single-cell sequencing (Human Cell Atlas): 400–600+ distinct transcriptional cell states. Including developmental & functional subtypes: possibly >1,000.
Human Cell Atlas (HCA) Answer.
Researchers estimate the human body contains roughly: ~37 trillion cells and ~400–500 major cell types. HCA aims to catalog them all.
Current Status (2025).
Over 3,600 researchers across 102 countries.
Datasets for more than 100 million human cells.
Dozens of organ atlases nearing completion.
