One factor implicated in active generation of cytosine methylation heterogeneity is activation-induced cytidine deaminase, which mediates DNA methylation changes and introduces epigenetic heterogeneity in normal germinal center B cells, the cells of origin of mature B-cell neoplasms such as diffuse large B-cell lymphoma and follicular lymphoma.
Activation-induced cytidine deaminase expression in diffuse large B-cell lymphoma with a paracortical growth pattern: a lymphoma of possible interfollicular large B-cell origin.
In follicular lymphoma and diffuse large B-cell lymphoma, the expression of AID mRNA was coincident with the presence of SHM in the variable region exons of the immunoglobulin heavy-chain gene.