# Cell Ontology (CL)

> Cell Ontology (CL): cell type classes for animals, such as T cell, B cell, neuron, hepatocyte and macrophage.

- Page: https://library.schematica.io/model/c3c433ad475d4e66b9ef335a726c5399
- Model type: Ontology
- License: CC BY 4.0
- Access type: Free
- Access method: Download
- Model size: Huge
- Formats: OBO, OWL
- Domains: Healthcare
- Audiences: Researcher, Data Scientist
- Classifications: #life-sciences #ontology
- External link: https://obophenotype.github.io/cell-ontology/
- Contact: Alexander Diehl (addiehl@buffalo.edu)
- Listed in library: 2025-06-12
- Last updated: 2026-10-23

## Use cases

### Sample Annotation (Healthcare)

Data scientists tag samples with CL cell types, so that they can compare data across studies.

### Cell Type Annotation (Healthcare)

Researchers annotate cell types in single-cell data with CL classes, such as T cell or neuron.

### Agent Grounding (Tech / IT)

AI agents check exact cell type names, such as cardiac muscle cell, before they tag text or answer questions.

## Description

## Overview
The Cell Ontology is a structured controlled vocabulary for cell types in animals. Classes in this entry include cell, T cell, B cell, neuron, astrocyte, hepatocyte, erythrocyte, macrophage, fibroblast and stem cell. Cell atlas and single-cell projects use it to annotate cell types. The entity count is the number of classes that CL itself defines in EBI OLS. It does not count classes that CL imports, such as anatomy classes. Researchers and data scientists can use this entry to find exact cell type names before they annotate samples or single-cell data.

## Top entities
cell, T cell, B cell, neuron, astrocyte, hepatocyte, erythrocyte, macrophage, fibroblast, epithelial cell, stem cell, cardiac muscle cell

## Mappings
- OBO Foundry identifiers (CL:): direct. Each CL class has an OBO ID, such as CL:0000084 for T cell.

## For agents
Look up cell type names in this entry, then read each class's definition and parents in EBI OLS. Anatomy classes in CL come from other ontologies, such as Uberon. Sample prompt: "Using the Cell Ontology (CL) entry in the Schematica Library, which CL classes are kinds of T cell?" Read via MCP: get_project_summary with graphProjectId c3c433ad475d4e66b9ef335a726c5399.

## Provenance
Publisher: None. License: CC-BY-4.0 (https://github.com/obophenotype/cell-ontology/blob/master/LICENSE). Version: 2026-06-08. Format: owl, obo. Described by the Schema Librarian on 2026-10-23; auto-cataloged.

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Source: https://library.schematica.io/model/c3c433ad475d4e66b9ef335a726c5399