This example shows a world map colored by deaths from brain and central nervous system cancer for 2019, using a yellow-orange sequential color scale. It renders geographic features with `d3.geoPath` and `geoNaturalEarth1`, pulling country shapes from world-atlas TopoJSON and matching them to CSV data via country codes. A mouseover tooltip appends the country name and death count, while a legend displays the color scale’s range. The code uses React hooks to load data and D3 v7 for mapping, with the topojson library for feature extraction.