(A) Morphology of the merging process of two types of organoids indicated by cell-tracker (red) hBVOs. (B, C) RT-PCR analysis for relative mRNA expression of ventral spinal cord genes, endothelial cells (EC), and blood-brain barrier (BBB) genes during hBVO and different hSCO coculturing. n=3, ns: p>0.05, * indicates p≤0.05, **: p≤0.01, ***: p≤0.001.