MCL1 and B-cell chronic lymphocytic leukemia: On the other hand, when MCL-1 was evaluated, we found that its upregulation induced by activated T cells was not consistently affected by opaganib and only reduced in a 40% by the presence of SKI-II, suggesting that the activation of SPHK1 might be involved, at least in part, in the upregulation of MCL-1 in CLL cells.