fetal cells from amniotic fluid can be coaxed into forming miniature balls of lung, kidney or small intestinal tissue. The technique hasn’t yet been used to treat any children, but the results show that is possible in principle. In a world first, Paolo De Coppi at Great Ormond Street Hospital in London and his colleagues have shown these lung organoids could potentially help guide the treatment of babies born with a sometimes-fatal lung condition called congenital diaphragmatic hern