I am working on cancer genomics. I downloaded TCGA BRCA FPKM data for my analysis. after some preliminary analysis, I categorised 250 samples in total 2 distinct categories. Now I want to analyse and compare their epigenetic and mutation patterns. After downloading all mutation and epigenetic data from TCGA BRCA, none of the samples from my previous analysis is matching. Suppose, TCGA-AN-A0AK-01A-21R-A00Z-07 sample is present in my previously downloaded FPKM data. But TCGA-AN-A0AK-01A-21W-A019-09 is available in the mutation data. Are these ids the same? For FPKM data and mutation data, do the same sample (individual) be represented by different Ids? Please help me, Thank you in advance.