In vitro studies of KIN-8194 in ibrutinib-resistant BTK^Cys481Ser-expressing WM and ABC DLBCL cells. (A) Dose-response curves for vector only, BTK^WT, or BTK^Cys481Ser transduced BCWM.1 and TMD-8 cells after treatment with ibrutinib or KIN-8194 for 72 hours. (B) Apoptosis analyses with annexin V-fluorescein isothiocyanate (FITC) and PI staining for native, BTK^WT-, and BTK^Cys481Ser-expressing BCWM.1 WM and TMD-8 ABC DLBCL cells after treatment with KIN-8194 or ibrutinib at the indicated concentrations for 16 hours. (C) Changes in pHCK^Tyr410 expression after treatment with ibrutinib or KIN-8194 at indicated concentrations for 1.0 hours in vector only, BTK^WT, or BTK^Cys481Ser transduced BCWM.1 and TMD-8 cells. (D) Changes in pBTK^Y223 and pERK1/2^T202/Y204 levels after treatment with ibrutinib or KIN-8194 at indicated concentrations for 1.0 hours in vector only, BTK^WT, or BTK^Cys481Ser transduced BCWM.1 and TMD-8 cells. The expression levels of total BTK and ERK1/2 in these cells and protein loading control GAPDH are also shown. KIN, KIN-8194.