Hello, I'm just starting in bioinformatics and bioconductor. It happens that I recently downloaded a microarray of gene expression (Affymetrix HT Human Genome U133 Array Plate Set) from TCGA (data level 3) glioblastoma and I'm interested in the expression of TGFb, but I couldn't find it in any of the rownames of the measures (which I think that are the codes of the genes). That means that the TGFb isn't mesured in this microarray platform?
You can always look up genes in NetAffx:
Also, I don't see your issue with the TCGA level-3 data (which provides one expression level per gene). For example, there is a value for TGFB1 in this file.
These arrays usually cover wide range of genes. I briefly checked the company's annotation list (link, scroll down), and could find TGFB1 in column name "Gene Symbol" row 1060.
Do you know when was your data collected? because old array sometimes does have much narrower gene lists.