Follicular lymphomas (FL) represent, together with diffuse large B cell lymphomas, the most frequent type of malignant lymphomas in Western countries. Biologically, FL represents the neoplastic equivalent of the normal germinal center (GC) reaction, recapitulating the cellular composition of reactive lymphoid follicles. The constitutive overexpression of the anti-apoptotic BCL2-gene inferred by the translocation t(14;18), leads to an accumulation of inappropriately rescued B-cells with a prolonged life span, allowing for the development of additional genetic hits, that are believed to be required for the establishment of FL. These biological features are mirrored in the clinical course of FL, which is highly variable. Some patients present with aggressive disease and die within one year, while others live up to 20 years. Therefore, treatment of follicular lymphoma is one of the most difficult and controversial topics in oncology. It is of major impact, that particularly the expression of genes from non-malignant bystander cells is strongly correlated to the clinical outcome of FL patients, thus revealing an important interplay between the malignant cells and their microenvironment.
Since there is accumulating evidence for the influence of single nucleotide polymorphisms on the prognosis of FL patients, it is highly desirable to characterize prognostically relevant SNPs, originating either from the tumor-relevant genes themselves, or from genes corresponding to the non-malignant bystander cells, to improve the risk-stratification of patients with FL.