* Nervous tissue: The cells in the nervous system, like neurons, have a limited ability to regenerate. While some repair is possible in the peripheral nervous system, damage to the central nervous system (brain and spinal cord) is often permanent. This is because neurons have limited ability to divide and form new connections.

* Cardiac muscle tissue: The heart muscle is specialized and doesn't easily regenerate. While some research is exploring ways to promote heart muscle regeneration, currently, damage to the heart muscle, as in a heart attack, can lead to permanent damage and scar tissue formation.

These tissues are considered highly specialized and have limited regenerative potential.