Any cell that divides to create two or more cells forms a clone. In our laboratory, we explore the fundamental principles governing clonal behaviour, whether during haematopoiesis, immune responses, embryogenesis, or cancer progression. We believe that by deeply studying clonal fate across functional and molecular dimensions, and integrating these insights, we can unlock the underlying mechanisms that shape biology in both health and disease. I will discuss the approaches and lessons we have learnt from studying haematopoiesis at a clonal level and how we're applying those for the study of cancer growth and metastases. These include our tools (lentiviral barcoding with SPLINTR, LoxCode in vivo barcoding), computational approaches (agent-based modelling, machine learning) and a new concept of "clonal memories" and "clonal destiny". Clonal memories are an inherited often hidden layer of information by cells with a common ancestor. Clonal destiny is how these memories, plus the present environment, shape future clonal trajectories, behaviours and functional destiny.