 Single cell sequencing, SCS, has revolutionized our understanding of multiple myeloma, millimetre. It has allowed us to gain insight into the genetic diversity within millimetre tumours, as well as the interactions between millimetre cells and their environment. This knowledge can be used to develop more effective treatments for millimetre patients. This article was authored by Meng Pingchen, Jinxing Jiang, and Jianhu.