BTK degraders overcome ibrutinib resistance in ABC DLBCL. (A) Immunoblots of TMD8 cells overexpressing WT- or C481S-BTK treated with the indicated compounds for 16 hours. (B) TMD8 cells overexpressing either WT- or C481S-BTK were treated for 3 days with the indicated compounds. Antiproliferative effects of compounds were assessed using a CellTiter-Glo assay kit (Promega), and ED₅₀ values were determined using GraphPad Prism nonlinear regression curve fit. (C) TMD8 cells were treated with the indicated compound combinations for 3 days. Plots show combination index (CI) scores. CI < 1 indicates synergy. GAPDH, glyceraldehyde-3-phosphate dehydrogenase.