All of these technologies have resulted in clinical relevant antibodies but most methods do not directly tap the potential of the human immune system. Indeed, the human immune system itself can safely be assumed to be the best in generating highly efficacious antibodies and these antibodies are most likely superior to those generated from mice or using phage display. In addition, such antibodies may have a better safety profile than antibodies derived from mice. Novel technologies to obtain monoclonal antibodies from human B cells include EBV transformation of antibody-producing B cells activated by TLR9-agonists [10, 11] and single cell PCR to obtain immunoglobulin genes from individual ex vivo isolated B cells [12, 13] . We have previously shown that with forced expression of BCL-6 in human B cells stable human monoclonal antibody secreting cell lines can be produced [14, 15] . We moved on to describe that ectopic expression of a constitutively active mutant of the transcription factor Signal Transducer of Transcription 5 (STAT5) in human memory B cells resulted in a differentiation block of activated B cells, preventing them to mature into plasma cells. STAT5 transduced cells resemble activated germinal center centrocytes and show enhanced survival and expansion [16] .