> For the complete documentation index, see [llms.txt](https://doc.duaer.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.duaer.com/getting-started/orthologs.md).

# Search orthologs in Duaer

In Duaer, search cross-species orthologs with Duaer Data (MyGene HomoloGene). One successful search uses 1 credit. This page includes the full English call skill.
## What you get

Orthologs in the Duaer data market lists cross-species genes in a HomoloGene group. One successful search uses 1 credit.

Add the node from the [Duaer Data category](/getting-started/duaer-data.md) (Orthologs), or copy the skill on the [data market](/getting-started/data-market.md). Related: [Genes](/getting-started/genes.md) and [Organisms](/getting-started/organisms.md).

## Search on the canvas

1. Open the node creator, select Duaer Data, then Orthologs.
2. Gene is required (a new node starts with INS). Species defaults to 9606; Ortholog species is optional (for example 10090 to keep mouse only).
3. Limit defaults to 10, max 20. Select Execute step.

A successful search uses 1 credit. Production deliverables land in the [data pool](/getting-started/data-pool.md).

## Call the API

- GET https://api.duaer.com/v1/data/orthologs?...
- Authorization: Bearer <Duaer key>
- gene is required.

For keys, refer to [Authentication for the Duaer public API](/api/authentication.md). Below is the same English call skill as Copy skill.

## Call skill

Same text as Copy skill on the Duaer data market. Keep it English.

```
---
name: duaer-orthologs
description: >-
  Search cross-species orthologs through Duaer (MyGene HomoloGene).
  One successful search uses 1 Duaer credit.
---

# Duaer orthologs

Search cross-species orthologs through Duaer with a Duaer key.

## Call

`GET https://api.duaer.com/v1/data/orthologs?gene=INS&species=9606&limit=10`

Header: `Authorization: Bearer <Duaer key>`

Use an account key or a model API key.

`gene` is required.

- `gene` — gene symbol or NCBI Gene id. Look up symbols with https://skills.duaer.com/genes.md.
- `species` — optional. NCBI taxonomy id for the query gene. Default `9606` (human). Look up ids with https://skills.duaer.com/organisms.md.
- `orthologSpecies` — optional. Keep only orthologs for this taxonomy id (for example `10090` for mouse).
- `limit` — optional. From 1 to 20. Default 10.

## Result

Each item has `source`, `title`, `url`, `summary`, `gene`, `geneId`, `name`, `taxId`, `organism`, `ensemblId`, `homologeneId`, `queryGene`, and `queryTaxId`.
Reuse `gene` when searching proteins, genes, expression, or targets.

## Credits

One successful search uses 1 credit.
An empty search, a failed search, a compound that matches nothing, or no remaining credits uses 0.
No remaining credits returns 402 and does not search.
A missing key returns 401.

```
## Questions

### What does Ortholog species do in Duaer?

It keeps only members for that taxonomy id; leave it empty to return every species in the HomoloGene group.

## Related

- [Search genes in Duaer](https://doc.duaer.com/getting-started/genes.md)
- [Search organisms in Duaer](https://doc.duaer.com/getting-started/organisms.md)
- [Search proteins in Duaer](https://doc.duaer.com/getting-started/proteins.md)
- [Search targets in Duaer](https://doc.duaer.com/getting-started/targets.md)
- [Use the Duaer data market](https://doc.duaer.com/getting-started/data-market.md)