I want to compare gene expression, in the way Gepia tool does by using log2(TPM) values. I have a condition which I would like to compare for a specific gene or set of genes with normal tissue expression (GTEx). I am thinking of comparing the log2(TPM+1) expression of normal tissue expression obtained from GTEx with the dataset I have. I don't have a normal expression dataset from my experiment. Is there something else that can be done such as Z-score (sample size~ 700(GTEx) vs ~22)? Or this approach is ok for the comparison?
PS. it is not a Differential expression analysis (motive is to take some idea, what is happening so that I can plan the next step of my study),
Thanks for your point. Do you think, a comparison of the house-keeping genes expression between GTEx and data I have, could give me some hints about the differences (Global shift) because of technical artifacts?