 The importance of the RDW, which is the coefficient of variation of the cell size, is crucial to detecting what kind of pathology may underlie an anemia. When there are qualitative defects in the cells, they reflect as variation in sizes. And so chronic eplasia, as you would have heard or known by now, is often associated with macrocytosis and increased RDW. It always tells you that there's a qualitative abnormality. In contrast, in transient eplasia, where there isn't a qualitative abnormality, but there is a transient suppression of the numbers of cells coming out, you would find that the indices would be normal, within normal, that is the sizes of the cells would not vary very much. So it's important to pay attention to the RDW as you look in perspective to pathophysiology.