Hi

I ran the third step in the RNASEQ protocol [mapping the reads to a repository using tophat and assemble it using cufflinks] with default options and default data [ mouse myoblast -28hr and 168 hrs]. I viewed the results of this run using a html viewer by connecting it to a repository query.  in the output, it shows the FPKM values of strand +1, -1 and 0. I can understand the values of + and - strands but what does this 0 stand for

I have attached a preview of this table too.

pls expalin