# Mean expression of a gene across experiments
**URL:** https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603
**Category:** Science
**Tags:** mouse, transcriptomics, analysis, how-to
**Created:** [June 18, 2020, 3:54am UTC](https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603 "2020-06-18T03:54:00Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@vbhave](https://community.brain-map.org/u/vbhave)
#### Post date: [June 18, 2020, 3:54am UTC](https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603/1 "2020-06-18T03:54:00Z")
I’d like to find a straightforward way to access the “average” expression of a gene across the entire mouse brain, or at least the information that would enable me to calculate some statistic like that. The goal would be to normalize a gene’s “expression energy” for a particular region, obtained using Structure Unionization, in order to get a sense of region-specific enrichment or depletion for genes with very different abundances. Really appreciate the guidance!
---
### Author:  [@amyb](https://community.brain-map.org/u/amyb)
#### Post date: [June 18, 2020, 11:12pm UTC](https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603/2 "2020-06-18T23:12:55Z")
Hi @vbhave,
Thanks for your question. Which data modality are you interested in using for your source? _In situ_ hybridization (ISH) data from the [Adult mouse brain atlas](http://mouse.brain-map.org/)? And have you had a look at [the API](https://help.brain-map.org/display/mousebrain/API) yet?
---
### Author:  [@vbhave](https://community.brain-map.org/u/vbhave)
#### Post date: [June 19, 2020, 3:21am UTC](https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603/3 "2020-06-19T03:21:29Z")
Yes, the adult mouse brain atlas. And I’ve taken a look – is the easiest way to pull expression statistics for all genes across the broadest ABA anatomical regions (e.g. for CH, CS, CB) and then average the values for each gene by combining the results from these queries? I’m just wondering if there is a more straightforward approach. Thanks for the help!
---
### Author:  [@jeremyinseattle](https://community.brain-map.org/u/jeremyinseattle)
#### Post date: [July 31, 2020, 4:25pm UTC](https://community.brain-map.org/t/mean-expression-of-a-gene-across-experiments/603/4 "2020-07-31T16:25:47Z")
Hi @vbhave. I don’t think anyone has addressed the exact question you are referring to; however, for your more specific question of how to get gene expression values for all genes in a single anatomical region, [this has been addressed in another thread](https://community.brain-map.org/t/extracting-data-for-all-genes-from-an-roi/507/3) (which it seems you were also a part of!). If you do find that this type of normalization improves your analysis of the [Adult mouse brain atlas](http://mouse.brain-map.org/) data, please let us know (for example, by posting a link to your future publication in this thread).