I work with TCGA (The Cancer Genome Atlas) database and I have downloaded mRNA gene expression microarray data concerning Breast Invasive Carcinoma disease. Subsets of the disease have been separated by tags, but i don't know the meaning of these tags. How can i mean these labels? For example, in Breast Cancer, there are 8 subsets for the disease (4 stages (I, II, III, IV) and 4 subtypes (Her2, Luminal A, Luminal B, Triple Negative)). Gene expression data for these eight subsets and normal subset have been given in a number of columns, so that the rows are gene names (17814 genes). There are 587 columns (samples) in this matrix that each column belongs to one of nine subsets (4 stages, 4 subtypes, 1 normal state). Top of each column exist a label, for example, TCGA-A1-A0SD-01A-11R-A115-07. What is this? I want to separate all columns related to Her2 state. How can i do this task? Please guide me.Thanks in advance!