Question: what are the main sources of immune system cytokines
[{'answer': 'macrophages', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 679, 'end_paragraph_id': 1, 'end_character': 690, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'B lymphocytes', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 692, 'end_paragraph_id': 1, 'end_character': 705, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'T lymphocytes', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 707, 'end_paragraph_id': 1, 'end_character': 720, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'mast cells', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 725, 'end_paragraph_id': 1, 'end_character': 735, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'endothelial cells', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 748, 'end_paragraph_id': 1, 'end_character': 765, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'fibroblasts', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 767, 'end_paragraph_id': 1, 'end_character': 778, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'stromal cells', 'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 792, 'end_paragraph_id': 1, 'end_character': 805, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '153663', 'title': 'Cytokine', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 869, 'bleu_score': 0.6863794710026151, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4362543231078948613}, 'section': 'Section::::Abstract.'}]}]