I have a two-part question:I am conducting the the analysis of mRNA expression data. I am using the TCGA datasets to check Pearson's correlation between my gene of interest and the other available ones.
1) I am using the median z-scores calculated by the TCGA pipeline to check correlation between genes. Would it be useful to utilise raw expression data instead of z-scores to calculate correlation?
2) Does high correlation(>0.6) indicate that the genes in question have a similar role or are involved in the same biochemical process? The exact function of my gene of interest isn't established yet, so I am trying to atleast guess where it could potentially be involved.