Besides the obvious: rampant infection. No, I'm toying with a version of the good ol' super-soldier trope. Specifically, obliterating the immune system and rejection response so as to allow for extensive and invasive augmentations, which would obviously require living in an environmentally sealed suit to protect from pathogens. So, I'm wondering more about internal implications of having no immune system. I've read that it helps preclude and control the growth of tumors, that kinda thing - health complications not from infection by an external agent, but from the absence of the functions the immune system serves internally. I'm working on researching this myself, but wouldn't mind input from someone who might know more about this than I do. Thanks in advance.