Which cell is unspecialized?

Unspecialized cells are also called stem cells. Stem cells are specific cells which didn't undergo differentiation yet. This means they can essentially be differentiated into any other cell. This idea has been already tested, although it has gained and achieved some controversy due to the ethical issues it brings with itself.

Stem cells are unspecialized, they can develop into many different types of cells and fill in for their roles in the body. However, stem cells also have their restrictions.