The latest issue of Philosophical Transactions B looks at the opportunities for the use of human pluripotent stem cells (PSCs), both from embryos and from the reprogramming of adult cells, as a scalable alternative to using human tissue for bio- and regenerative medicine applications. These special cell types have the ability to change into different types of cells, which promises an unlimited supply of human somatic cells, allowing for precise modelling of human biology ‘in a dish’ and the possibility of novel cell based therapies for the clinic. We spoke with one of the Guest Editors, David Hay from the University of Edinburgh, about the issue.