JUN and Burkitt lymphoma: It is plausible that during the early stages of tumorigenesis, the basal activity of the Ig enhancers leads to MYC gene expression, while the MYC/JNK/AP1 pathway amplifies the activity of the enhancers and thus sustains the high expression levels of MYC and BCR, both of which are directly associated with the malignant transformation of BL cells.