Cuffdiff - NO TESTED isoform

[lucasmiguel]

Hi !
I have one question. Analysing one gene differentially expressed by Cuffdiff, i saw that all of your isoforms are not differentially expressed. BUT the isoform that makes the gene be differentially expressed is NOT TESTED ( your FPKM is the highest in comparison of others isoforms ).

My question is: Cuffdiff removes the highly expressed isoforms and after testing them, he sum all FPKM of all isoforms for analyze the gene?

this explain why i have genes differentially expressed with no one isoform differentially expressed, right?

Thanks to all.