Beside Btk, the direct inhibitory activity of IQS019 towards Syk and/or Lyn phosphorylation may also explain the capacity of the compound to activate apoptosis in vitro and in vivo, as pharmacological inhibition of Syk, has been reported to elicit the apoptotic cascade in preclinical models of DLBCL and CLL [35, 36]. This evidence concerns the gene LYN and B-cell chronic lymphocytic leukemia.