The Nagalase enzyme has the ability to completely shut down the activity of the localized immune macrophage cell, whose job it is to destroy any cell that has been harmed or is not functioning normally. It effectively “cloaks” the cancer cells from detection by the immune system. This is the reason that someone can have a strong functioning immune system and still be growing a tumor. The Nagalase blood test is a good way to check the progress of treatment.