As we are approaching the 100th anniversary of the discovery of insulin, a wide array of its signaling pathways has been defined. However, the initial step in insulin action, i.e. the engagement with its cell-surface receptor and the resulting conformational change, which propagates across the plasma membrane to the intracellular module, remains poorly understood. Addressing this problem, researchers from the Paul Langerhans Institute Dresden of the Helmholtz Zentrum München at the University Hospital Carl Gustav Carus of TU Dresden together with colleagues from Rockefeller University New York succeeded for the first time in the visualization of the insulin receptor activation. The results of this collaborative work have now been published in the Journal of Cell Biology.