Fig. 2: Spatial expression analysis of genes identified by differential expression analysis (DEA) along a linear trajectory.

a A surface plot provides a visual representation of the trajectory’s course (indicated by an arrow), complemented by a barplot illustrating the proportion of histological groups along this trajectory. b and c Surface plots offer insights into the gene expression patterns of genes predominantly localized within their respective assigned areas. Error bands of line plots indicate the confidence interval (level: 0.95). d–g Heatmaps present the expression profiles of the top 18 differentially expressed genes (DEGs) per histological group (as referenced in Fig. 1e). Notably, while these genes have been identified as unique DEGs, those from the tumor and transition regions do not consistently exhibit confined expression patterns to their designated areas, in contrast to DEGs from the (infiltrated) cortex. e–h Line plots and surface plots further elucidate the expression patterns of selected genes, demonstrating how they may traverse area boundaries in various ways. Error bands of line plots indicate the confidence interval (level: 0.95).