TCGA normal vs control sample

Question

[manali.rupji]

Hello All,

In the TCGA database, based on the barcode, 01-9 are tumors, 11-19 are normals and control samples are labeled 20 - 29. I am unable to find in the TCGA documentation what is the difference between the controls and normals?

I understand normals are surrounding tissues that are used from the same individual.

Thanks in advance,