Final answer:
Three factors that contribute to autoimmunity are genetic susceptibility, environmental triggers, and a breakdown in immune tolerance.
Step-by-step explanation:
For autoimmunity to occur, three factors must contribute: genetic susceptibility, environmental triggers, and a breakdown in immune tolerance.
Genetic susceptibility means that certain individuals are more prone to developing autoimmune diseases due to their genetic makeup. Environmental triggers, such as infections or exposure to certain chemicals, can stimulate the immune system to react against self-antigens. Additionally, a breakdown in immune tolerance refers to a failure of the immune system to distinguish between self and non-self, leading to the immune system attacking its own tissues and organs.