For example, in non-Hodgkin's lymphoma, although TNF polymorphisms have been shown to influence treatment outcome, progression-free survival and overall survival of patients (Warzocha et al, 1998), in myeloma TNF and lymphotoxin α polymorphisms are associated with increased risk of the disease, but no overall increase in survival (Davies et al, 2000). Here, TNF is linked to plasma cell myeloma.