In cell biology, a precursor cell, also called a blast cell or simply blast, is a partially differentiated cell, usually referred to as a unipotent cell that has lost most of its stem cell properties. A precursor cell is also known as a progenitor cell but progenitor cells are multipotent. Precursor cells are known as the intermediate cell before they become differentiated after being a stem cell. Usually, a precursor cell is a stem cell with the capacity to differentiate into only one cell type. Sometimes, precursor cell is used as an alternative term for unipotent stem cells. In embryology, precursor cells are a group of cells that later differentiate into one organ. A blastoma is any cancer created by malignancies of precursor cells. Precursor cells, and progenitor cells, have many potential uses in medicine. , there is research being done to use these cells to build heart valves, blood vessels and other tissues, by using blood and muscle precursor, or progenitor cells.