NALM6 cells were obtained from ATCC. NALM6 CD19−/− were generated as previously described60 (link). NALM6 were transduced to express GFP and firefly Luciferase (FFLuc) for in vitro and in vivo detection37 (link). Cells were cultured in RPMI 1640 (Corning) with 10% FBS (Hyclone) 1x NEAA, 2mM GlutaMAX, 100U/mL Pen, 100μg/mL Strep, 2mM HEPES (Corning) and 55μM 2-ME). For Incucyte-based analysis, NALM6 CD19+ and NALM6 CD19−/− were transduced with Incucyte NucLight Red lentiviral reagent (NLR, Essen BioScience) and selected with puromycin according to manufacturer’s instructions.