This example shows side-by-side boxplots comparing the age distribution of 100 skin cancer patients by sex, with age on the y-axis and sex on the x-axis. The plot uses d3.csv to load patient data, d3.nest with rollup to compute quartiles, medians, and interquartile ranges, and d3.scaleBand and d3.scaleLinear for axes. Boxes, median lines, and vertical whiskers are drawn as SVG rect and line elements. The data source is a remote CSV file, rendered with d3.v4.