marrow
bone marrow

But I knew him well, right down to his bone marrow.

The cause was cancer of the bone marrow, the newspaper said.

If you have it, your bone marrow doesn't make enough new blood cells.

Many cultures have used bone marrow as food throughout history.

These cells are found in the bone marrow and other parts of the body.

By adulthood, only about half of the bone marrow is red.

The same cannot be done for bone marrow because it is the immune system.

Would he donate some of his bone marrow, they asked.

Last summer, I donated bone marrow for my brother, who is now doing very well.

Healthy red blood cells are made in your bone marrow.