In biology, liquefaction often involves organic tissue turning into a more liquid-like state.

In March of that year, the Reagan Administration imposed a moratorium on Federal financing for all medical research involving fetal tissue.

Neuroma cutis is a relatively rare type of neuroma, or tumor involving nervous tissue, in the skin.

At that time, the Government suspended Federal financing of new research involving human fetal tissue until the ethical issues could be resolved.

What stirred the current interest in such implants was a medical breakthrough that did not involve fetal tissue.

An artificial pancreas system does not involve synthetic or artificial tissue or organs.

The surgery involves donated tissue.

An arguably more reasonable scenario is a partial brain transplant involving only enough tissue to provide key memories and a sense of continuity of identity.

Surgery involving reproductive tissue affects reproductive function and fertility.

He performed research of nerve fibers and the myelin sheath, and conducted studies involving connective tissue.