LYN and acute lymphoblastic leukemia: Flow cytometry of primary ALL cells treated with NVP-BEP800 showed a reduction in tyrosine phosphorylation of LCK (p-LCK) in T-ALL cells (P < 0.0001) and tyrosine phosphorylation of LYN (p-LYN) in B-ALL cells (P < 0.001) (Fig. 3c).