The function of c-myc in physiology is only partially known. Its product has DNA 
binding properties and plays a role in the control of proliferation and 
differentiation. In general, increased c-myc expression leads to proliferation 
and abolishment of differentiation. The involvement of c-myc in mouse 
plasmacytomas and human Burkitt's lymphoma is well known: due to chromosomal 
translocation c-myc comes under the influence of regulatory elements of 
immunoglobulin genes, leading to increased expression of the gene and 
proliferation of the cells. In man, the chromosomal translocations may occur 
within the increased pool of (pre) B-cells due to Epstein Barr virus (EBV) and 
malaria infection with subsequent immunosuppression. Apart from these early 
(primary?) events in lymphomagenesis, c-myc is also often involved in tumour 
progression, probably by a similar mechanism. Different types of c-myc 
involvement are associated with specific types of lymphoma: there are 
differences between endemic, sporadic and ileocecal Burkitt's lymphoma as well 
as between those and primary extranodal large cell lymphoma and large cell 
lymphoma which has progressed. These differences are associated with the 
differentiation of the involved lymphoid cells and may point to the stage of 
differentiation in which the oncogenic event occurred.