This example presents an interactive bubble tree visualization of hierarchical medical data. It displays a collapsible node-link diagram where clicking a node reveals its children, recentering the tree, and showing detailed information about the selected item in a separate panel. The visualization uses D3.js v6 with SVG rendering and smooth transitions, loading data from a remote JSON file hosted on GitHub. The chart dynamically sizes node radii based on the number of children and categorizes nodes by their medical descriptions. The code also demonstrates recursive tree traversal and data categorization logic within a React framework.