BTK and mantle cell lymphoma: The most potent compound (17, Figure 7) in which they introduced a pyridine nucleus instead of phenyl one in C-3, showed potent BTK inhibition (IC50 = 36 nM) and completely inhibited PLCγ2 phosphorylation in Z138 cells at a low micromolar concentration, as well as exerting antiproliferative activities in MCL cell lines (IC50 values < 1 μM), and inducing cell apoptosis in Jeko-1 and Z138 cells.