Pluripotent stem cells generated from patient samples are increasingly employed to explore disease mechanisms in the lab and test novel therapeutic strategies. Stem cells derived from patients can be cultivated in vitro to produce aggregates of cells that mimic the basic architecture of specific organs in 3D. For patients affected from complex genetic diseases such as primary ciliopathies (characterised by defects in major organs including brain, kidney, eye, liver and skeleton), this new approach offers the unique opportunity to understand how a patient’s specific mutation can lead to disease in a way that considers the unique genetic background of each patient. (By Dr. Virginie Sottile, https://jmg.bmj.com/content/early/2022/02/18/jmedgenet-2021-108315 )