Extended Data Figure 5. Low-burden metastatic cells have tumour-initiating and differentiation capacity.

a, Schematic overview of orthotopic transplant experiments to investigate the tumour-initiating and differentiation capacity of low-burden metastatic cells. Images of resulting grafts show that 2/4 transplants of low-burden cells grew large tumours, while 0/10 transplants from primary tumour cells developed tumours. b, Unsupervised hierarchical clustering of tumour cells derived from transplants of low-burden metastatic cells. Transplant-derived tumour cells were clustered with metastatic and primary tumour cells from previous experiments (Extended Data Fig. 3a) to investigate their differentiation status. Transplant-derived tumour cells were heterogeneous, where 1.3% of them were basal/stem-like, and 98.7% of them clustered with more luminal-like cells. This shows that low-burden basal/ stem-like metastatic cells have the capacity to give rise to luminal-like cancer cells.