The body should function passively, in coordination with and in reaction to internal signals that maintain proper functioning and good health. Humans do not have immunity to intracellular animal pathogens, which do not merge peacefully in the human body. Intracellular pathogens live off the energy made by the cell, damage cell function, disperse abnormal proteins and debris, infect immune cells, trigger angiogenesis (new blood vessel growth), and interfere with normal apoptosis (normal cell death). The pathogen is protected from an immune system attack by the cell wall, and the ability to hide inside other pathogens. Over time, a futile immune system attack generates redness, heat, swelling, pain, scarring, bio-film, pus, plaque, sticky, clogging, erosion, and atrophy, during an ongoing infectious cascade of events.