Viruses have the ability to remain in the host cell in a dormant state or latent state for many years. This is a part of reproduction cycle of a virus called the lysogenic cycle. This causes persistent infection in the host because the virus remains in the host cell and cause infection.
This persistent infection can cause cancer in the host because the viral genome incorporates in the host cell genome and take controls on its gene machinery. For example, HPV can incorporate itself in the host genome and can alter it which can cause cancer. So the correct answer is persistent infection.
Myofibrils are the building blocks or contractile unit of each muscle fiber. The tiniest functional unit of skeletal muscle, the sarcomere, is found in the myofibrils and is made up of protein filaments: actin (thin) and myosin (thick).
