The basal and BCR induced phosphorylation of LYN and JNK were considered by immunoblottting. Cell emergency signs were evaluated by apoptosis using flow cytometry. We confirmed that LYN was constitutively phosphorylated in MCL cell lines and in 9/10 leukemic MCL cases. Treatment with dasatinib or with a specific inhibitor of Ganetespib cost Src kinases including PP2 suppressed constitutive LYN service and increased in vitro spontaneous apoptosis of primary MCL cells. BCR involvement triggered an increase of LYN phosphorylation leading to activation of c JUN NH2 terminal kinase and over-expression of early growth response gene 1. Inhibition of JNK with SP600125 induced apoptosis and paid down amount of basal and BCR induced expression of EGR 1. Furthermore, decreasing EGR1 expression by siRNA paid off BCRinduced cell survival. Treatment with PP2 or with dasatinib suppressed BCR caused LYN and JNK Mitochondrion phosphorylation as well as EGR 1 up-regulation and is associated with a decrease of cell survival in every cases analysed. . This study shows the value of BCR signaling in MCL cell survival and points out for the efficiency of kinase inhibitors in suppressing proximal BCR signaling functions and in inducing apoptosis. Keywords: Mantle cell lymphoma, LYN, BCR, EGR 1, Dasatinib Background Mantle cell lymphoma constitutes about 10% of non Hodgkin lymphoma and despite recent developments in the therapy, the condition hasn’t generally been treated with a bad progression free survival for a large number of patients. New treatments that target specific signaling molecules are consequently of potential benefit. Lately, some studies tried to show new ideal therapeutic targets and have HSP inhibitor clarified the impact of several signaling pathways for increased proliferation and resistance to apoptosis of MCL cells. Constitutively active B cell receptor mediated signaling has been implicated in the pathogenesis of quite a few NHLs including diffuse large B cell lymphoma, follicular lymphoma, gastric mucosa-associated lymphoid tissue lymphoma and B cell chronic lymphocytic leukaemia. Lately, we demonstrated in major MCL cells a central position for active BCR signals in survival of MCL cells. The activated forms of the BCR associated kinases LYN and spleen tyrosine kinase were present in MCL tumor tissues therefore supporting an in vivo function of active BCR signaling in this pathology. More over, MCL is characterized by a highly restricted immunoglobulin gene repertoire with stereotyped VH CDR3s and precise Somatic Hyper Mutation targeting, ergo strongly implying a role for antigen influenced collection of the clonogenic progenitors. Upon antigen diamond, Ig IgB heterodimer are phosphorylated on immunoreceptor tyrosine centered activation motif tyrosines by the BCR related kinase LYN, which belongs to the Src family kinases. Early BCR induced genes were discovered by qRT PCR range.