I would like to compare several genes expression between 2 populations (of cells) as a whole.
I compared each individual genes expression using a log+z-score transformation before applying a statistical test (a one-sided t-test) to look for individual gene downregulation.
Now I would like to compare n genes at the same time between the 2 populations and check if I have a general downregulation or not.
Can I apply the same method ? Or z-scores do not make sense when comparing different genes together ?
Thank you very much for your help !