Assertion: immune system's cell | /r/HasProperty | needed
Facets:
value: no longer
type: TEMPORAL
Source sentences:
text: What researchers do know is that the body continuously makes immune cells that are called white blood cells, or leukocytes, and it generates far more cells of the adaptive system — known as lymphocytes — that mature into B cells and T cells than are needed.
text: When you’re asleep, a portion of that energy is used by the immune system—to create new cells and get rid of old cells that are no longer needed.