IL7 and acute lymphoblastic leukemia: To test if increased lymphopoiesis due to excess IL7 is directly responsible for reduced ALL growth in vivo, we treated mice transplanted with B-ALL cells with recombinant IL7 complexed with a neutralizing anti-IL7 (aIL7, clone M25) monoclonal antibody (Figure 4—figure supplement 1A), which increases the half-life of recombinant IL-7 in vivo (Boyman et al., 2008).