English: A — Microinjection of brain organoids in mice brain led to engraftment and invasion by host vasculature. B — Co-culture of PSCs with endothelial cells; and C — genetic engineering of inducible transcription factor ETV2 in hESCs led to vascular system development in brain organoids. D — EBs early fed with endothelial factors such as VEGF and later with WNT7 display vascularization along with neuronal differentiation. E — Different fusion approaches led to brain organoid vascularization include fusion of (i) neural and mesodermal spheroid (ii) brain EB sandwiched with vascular EB in a Matrigel droplet (iii) brain EB and dissociated vascular organoids.