This bar chart displays average expression levels for two genes, Gene X and Gene Y, computed from a CSV dataset loaded via d3.csv. It summarizes the data by showing the mean expression value for each gene as a pair of steel-blue bars that turn orange on hover. The visualization uses D3 v7 scaleBand and scaleLinear to position the bars and axes, with d3.axisBottom and d3.axisLeft generating the scales. A summary paragraph above the chart reports the sample count and computed averages, using d3.mean for calculations. The SVG rendering includes axis labels for both dimensions.