JAK3 and lymphoma: First, we transduced the IL-2 indicator cell line MO7e with lentiviral expression vectors encoding the wild-type form of JAK3, the constitutive-active, and lymphoma-associated variant JAK3-A572V (17), or the JAK3-R840C variant, and analyzed IL-2-dependent growth at increasing IL-2 concentrations (Figure 3C).