 Solution

Bulk RNA sequencing mixes the gene expression of all sampled cells, while dissociated-cell measurements retain individual profiles but usually lose their original neighbours and positions. Spatial transcriptomics preserves those relationships. The same cell type can behave differently at a tissue boundary, near a blood vessel or beside a tumour, so position can explain a state that a cell-type label alone cannot.

Spatial measurements can reveal tissue layers, developmental boundaries, tumour–immune interfaces and subcellular RNA localization. They can distinguish a change in cell abundance from a change in expression within a particular anatomical niche. Dissociation can also lose fragile cells or induce stress responses.

Spatial proximity supplies context, not proof of communication. Adjacent expression of a ligand and receptor suggests an interaction to test; establishing signalling requires additional evidence and perturbation.