BTK and mantle cell lymphoma: To investigate the mechanisms in overcoming resistance in MCL, we performed in vitro studies of JeKo-1 ibrutinib-sensitive cells, JeKo BTK KD_2 cells with intrinsic resistance to BTK inhibitors, and JeKo-IBN-R cells with acquired resistance to ibrutinib, Mino venetoclax-sensitive cells, and Mino-VEN-R cells with acquired resistance to venetoclax.