Why does the normal tissue increase while I try to select the tumor purity great than 60%

Question

[nuorain]

Hello,

I am working on TCGA-COAD data. At the beginning, from the barcode information, the normal tissue is 41. After I use the command purityDATA <- TCGAtumor_purity(colnames(dataPrep1), 0, 0, 0, 0, 0.6) to select the tumor purity which is greater than 60%, there are 42 filtered samples. Why does the number change to 42? Why is not 41? I don't understand. Can anyone help me out? Thank you very much.

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