This line chart visualizes the relationship between Gene X and Gene Y expression levels across a dataset, using a smooth monotone curve to show the trend. The D3.js v7 code loads CSV data, sorts it by Gene X expression, and maps the values to linear scales for the x- and y-axes. It renders an SVG line path with labeled axes and a title, employing `d3.scaleLinear`, `d3.line`, and `d3.curveMonotoneX`. The chart is styled with a white background, rounded corners, and a soft shadow.