Characterization of S63845 resistant cells reveals heterogeneous resistance profiles. (A) Dose-response curves of S63845-sensitive vs -resistant cells indicate a >10-fold shift of IC₅₀ values. Viability was assessed 72 hours after treatment (n = 3 biological replicates). (B) Lack of BAK activation after treatment with S63845 in resistant cells. BAK activation status was determined 4 hours after treatment with 100 nM S63845. Graphs represent the mean (horizontal lines) of 3 independent experiments. ***P < .001. (C) Baseline protein levels of Bcl-2 family members show cell line–specific adaptations in OPM2-S63845- vs KMS12BM-S63845-resistant cells. (D) Assessment of baseline BH3 family binding patterns in S63845-sensitive vs -resistant cells (n = 2 biological replicates). *Immunoglobulin light chain. (E) Top 20 significantly deregulated pathways in S63845-sensitive vs -resistant cells, as determined by the Ensemble of Gene Set Enrichment Analysis (EGSEA) method. (p.adj., adjusted P-value). (F) Hierarchical cluster analysis demonstrates a closer association between individual cell line pairs rather than sensitive vs resistant cell line status.