Mutant protein expression problem

Hi everyone, I just got protein expression problems, I wonder if anyone has experience to help me solve this problem.
I made a construct for a C. elegans mutant protein, with one of the two ecto domains deleted. I expressed it in 293T cells.
I found this mutant protein could not be expressed consistently, sometimes it is expressed very well, sometimes, there is completely nothing.
There is no pattern to follow.
I had been working with the wild type protein for a while and never got expression problem, it is always expressed well.
How to explain it?
Thanks in advance

Hi Jenny

I removed the duplicate post in the other section as I think you will get most answers in this section.


OK, no problem.