For the enrichment analysis, Gene Sets Enrichment Analysis (GSEA)[49] and Over-Representation Enrichment analysis (ORA)[50] were performed as supplementary analyses. GSEA is an alternative score-based approach that computes rank-based scores for prior gene sets, while ORA focuses on genes whose expression show significant spatial correlations with PC1 and tests whether they had a greater chance of belonging to a prior gene set than the background genes using one-side Fisher’s exact test [50]. Details can be found in the Supplementary Methods.
