About the unsecreted protein

The protein I mentioned here is those ones I was working on in Ashe lab. In detail they are Dpp C terminus fragment and the Sog fragment. I asked Stiring and Philip about this, Stiring suggested that it may be the problem in folding, and Philip suggested that it may be caused by the uncorrect cleavege of the premature protein.
No idea on how to fix this... though...