It has been seen that the polymorphism (Ser608Leu) of the NOS2A gene, which codes for inducible nitric oxide synthase (iNOS), determines a greater enzymatic activity and subsequent increase in nitric oxide (NO) [144]; this polymorphism has been found in many cases of NHL, particularly in subtypes DLBCL and FL. This evidence concerns the gene NOS2 and non-Hodgkin lymphoma.