In contrast to the type II-like latency observed when the ΔEBNA2 + Myc cord blood cell lines were grown in vitro on the CD40L/IL21 expressing feeder layer (Fig 1B), we found that the ΔEBNA2 + Myc lymphomas, in addition to losing LMP1 expression, also express high levels of the EBNA3A (Fig 3B) and EBNA-LP (S1B Fig) proteins, similar to Wp-restricted human BLs, although unlike Wp-restricted human BLs they do not express the EBV BCL2 homologue, BHRF1 (Fig 3C). Here, IL21 is linked to lymphoma.