The immune system has been the focus of rapid and exciting research over the last decade. An overactive and misguided immune system stimulates the development of autoimmune disorders, whereas primary/acquired immunodeficiency disorders result from a sluggish functioning of the system. The system is also known to mount abnormal and sometimes severe allergic responses to harmless antigens in the environment.

Histiocytic disorders, on the other hand, are a category of rare and therefore poorly understood and difficult to diagnose and treat diseases of cells of the innate immune system known as histiocytes. Histiocytes may either comprise the specialized macrophages stationed in connective tissues or may be dendritic in nature and derived from the Langerhans cells of the skin. Both the cell lineages evolve from the CD34 cells ...