Sentence: In addition , biochemical examinations revealed that docetaxel could induce phosphorylation of both bcl-2 and c-raf-1 , but these changes were inhibited when tumor cells were pretreated or simultaneously treated with doxorubicin .
Drug combination annotation:
[{'class': 'NEG', 'spans': ['docetaxel', 'doxorubicin'], 'is_context_needed': False}]