truncate gtex row names?

[willwerscheid]

Would it be enough to just include the ensembl IDs, without the additional info (chromosome number, etc)? Thoughts @pcarbo ?

[pcarbo]

The additional info is probably about the SNP that is associated with the expression of that gene (which is where the association z-score came from). I don't know how important that is to you—feel free to remove it if you'd like.