While using GTEx portal to find out tissue specificity of certain genes, I found that median TPM of these genes = zero, I just need to ask if the median TSM of certain gene in certain human tissue = zero, this means that the gene is not found in this human tissue or maybe it is found but not expressed.
If there is an easy resource to let me understand this issue, please provide me.

![TPM pf certain genes in certain tissues][1]

[1]: ibb.co/XbnF3TP

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