My data consists in two samples relative to the expression of a given gene, with 4 replications in both samples.
I am interested in testing whether the two samples come from the same population, taking into account the fact that I have repeated measures by design.
I've been reading about different non-parametric approaches and the Friedman's test seems to be one option. However, given the extremely low sample size, I am not quite sure that this test can be adopted.
Can you suggest if I can proceed this way? Can/should other approaches be adopted?
alternatively, would any exact test would be ok for my specific need?