you might want to check what kind of antibody you used. Polyclonal antibodies tend to have more nonspecific binding and thus can bind to more than just the CYP of interest. This can happen with some monoclonal antibodies too, so you do need to check carefully. I would suggest calling the manufacturer. the other possibility is a bleed through from one channel to the other e.g. your nucleus stain was extremely bright and was also picked up by the channel used to image only the CYP.