IL7 and lymphoma: Furthermore, we found that stable cell lines derived from the ΔEBNA2 + Myc lymphomas (grown off the feeder layer) also often express one or more pre-B cell and/or pro-B cell associated proteins (S4 Fig) and respond to IL7 cytokine treatment by inducing STAT5 tyrosine phosphorylation (Fig 7C), indicating that the IL7R is functional.