Dear All,

I am comparing the gene expression between two cell types by examining the Cufflink output file -- gene differential expression testing. The file lists the FPKM of genes in two cell types and log2 of fold. I want to look for genes that have more than 2-flod of expression in cell type A than in cell type B. What is the minimum FPKM in cell type A so that only the genes that have FPKM highier than this number can be taken into consideration for further analysis? 

For example,

The FPKM of gene X in cell type A is 80, and in cell type B is 20, the fold of difference is 4.

The FPKM of gene Y in cell type A is 4, and in cell type B is 1, the fold of difference is also 4.

Is there a minimum FPKM in cell type A for genes to be selected for further analysis?

Thanks.

Jianguang