Most people don't know they have it because the disease can lie dormant for decades.

FORBES: Magazine Article

Lupus can lie dormant for long periods of time--the idea was that Benlysta only works if the immune system is actively attacking the body.

FORBES: Health Care

Tuberculosis can lie dormant in a person for years and then strike when the immune system is weak.

BBC: NEWS | Health | Breathalyser detects tuberculosis