Human cell division involves hundreds of proteins at its core. Knowing the 3D structure of these proteins is pivotal to understand how our genetic material is duplicated and passed through generations. The groups of Andrea Musacchio and Stefan Raunser at the Max Planck Institute of Molecular Physiology in Dortmund are now able to reveal the first detailed structure of a key protein complex for human cell division known as CCAN. By using cryo-electron microscopy, the researchers show important features of the complex’s 16 components and challenge previous assumptions about how the complex is able to recognize the centromere, a crucial region of chromosomes in cell division.