# Opentargets targets protein class

**URL:** <https://community.opentargets.org/t/opentargets-targets-protein-class/1654>\
**Category:** General\
**Tags:** ot-platform\
**Created:** [29 January 2025 17:28 UTC](https://community.opentargets.org/t/opentargets-targets-protein-class/1654 "2025-01-29T17:28:34Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![hcornu](https://dub1.discourse-cdn.com/flex017/user_avatar/community.opentargets.org/hcornu/32/716_2.png) [@hcornu](https://community.opentargets.org/u/hcornu)\
**Post date:** [31 January 2025 15:24 UTC](https://community.opentargets.org/t/opentargets-targets-protein-class/1654/2 "2025-01-31T15:24:03Z")

</div>

Hi @koryclick,

Thanks for your question.

Target Class is an annotation we get from ChEMBL’s protein class data (the classification that you see in a ChEMBL target report card in the ‘Protein Target Classification’ row).

[Their publication describes the classification:](https://pmc.ncbi.nlm.nih.gov/articles/PMC3245175/) protein targets are classified into a manually curated family hierarchy, according to nomenclature commonly used by drug discovery scientists (not aiming to be comprehensive).

Finally, it’s a [known issue that targetclass\_id has been missing since ChEMBL32](https://community.opentargets.org/t/missing-targetclass-id-in-23-06-targets-json-and-parquet/1448). We’ve raised it with ChEMBL.

Let us know if you have further questions!

---

_[View the full topic](https://community.opentargets.org/t/opentargets-targets-protein-class/1654)._