Same patient ID, multiple TCGA studies: mRNA z-score (RNA Seq V2 RSEM)

Question

[neuro3030]

Very basic question: in three different studies included in the TCGA, I see 3 different z-scores for the same patient. How do I resolve this so that I can combine multiple studies? Also, if there is this much variability in the same patient, is it not valid to compare RSEM values between studies for the same gene? Thanks

[Kevin Blighe]

What do you mean by 'study' - different cancers? Also, can you point out from where you got the data? There are so many ways to obtain TCGA data at this stage, it's very important to understand how you got it. Thanks.