BCL2 and neoplasm: In particular, celastrol has been shown to inhibit NF-kB and B-cell leukemia/lymphoma 2 (Bcl-2) signaling pathways, as well as increase the expression of the Bcl-2-associated X (Bax) protein and caspase, involved in the induction of the apoptosis of several types of tumor cells, including breast cancer.