Whilst in germinal centre DLBCL the process of somatic hypermutation appears to remain ongoing and active in the malignant cells [172,187], in follicular lymphoma the clinical data from repeat analysis of immunoglobulin heavy chain gene sequences through the natural history indicates that whilst AID is still expressed there is little or no on-going somatic hypermutation in follicular lymphoma cells, [188-190]. The gene discussed is SLC3A2; the disease is follicular lymphoma.