Glutathione is the sole protector of your immune cells allowing them to reproduce explosively when needed.
This includes killer “T” cells (a subtype of white blood cell that plays a central role in cell-mediated immunity – Wikepedia) and Macrophages (a type of white blood cell that engulfs and digests cellular debris, foreign substances, microbes, cancer cells, and anything else that does not have the types of proteins specific to healthy body cells on its surface – Wikepedia)