docs/notebooks/data/data2_disease_hierarchy.csv
gastric ulcer;stomach disease;digestive system disease;respiratory&digestive disease
gastritis;stomach disease;digestive system disease;respiratory&digestive disease
flu;respiratory infection;vascular lung disease;respiratory&digestive disease
bronchitis;respiratory infection;vascular lung disease;respiratory&digestive disease
pneumonia;respiratory infection;vascular lung disease;respiratory&digestive disease
stomach cancer;stomach disease;digestive system disease;respiratory&digestive disease