Non-Hodgkin's lymphomas (NHL) are a heterogeneous group of neoplasms with wide variation in histologic features, immunologic phenotype, molecular abnormalities, clinical presentation, and disease progression. New molecular techniques have significantly increased understanding about the molecular background for development of NHL and it has been possible to identify typical genetic abnormalities in specific NHL subtypes. Some of the genetic changes and alterations in predisposing genes related to NHL are reviewed in this article. The reviewed information suggests that it is of great importance to look for reliable diagnostic tools for screening of population groups to identify individuals at high risk of lymphomas. The follow up of interaction of various predisposing genes and environmental factors in lymphoma pathogenesis is of considerable public health importance as well. In a pilot study, polymerase chain reaction-restriction fragment length polymorphism based genotyping assays were used to determine the frequency of polymorphisms in genes coding for various biotransformation enzymes in a case-control study comprised of 147 patients with NHL and group of age- and sex-matched unrelated healthy Czech individuals. Preliminary statistical analyses showed no association of CYP1A1-m1/m2, CYP2E1-c1/c2, GSTM1null, and GSTT1null genotypes with incidence and status of NHL. On the other hand significant differences in distribution of genotypes of CYP2E1-intron 6, EPHX-exon 3, and GSTP1-exon 5 were observed between cases and controls. Thus it seems that study of co-segregation of particular genotypes of biotransformation enzymes with higher risk of lymphoproliferative disorders may prove to be very useful approach in elucidation of the etiology of malignancies of lymphoid origin.