Min FPKM Value for Diff Exp

[pcg]

Hi all,

Im wondering do people pre-filter their FPKM values when looking at differential expression. So for instance the levels of expression must be a minimum FPKM > 1 or do people just leave their FPKM values alone.

I have noticed that there can be big ln fold changes > 20 but when examining the FPKM values they are 6.4E-11 vs 0.0481. Surely such FPKM values are really negligible