Extended Data Figure 6: Vascular mimicry in 4T1-T and pooled primary tumours.

a, PAS/CD31 (left) and PAS/mCherry (right) staining of serially sectioned 4T1-T derived primary tumours, where the tumour cells constitutively express an empty vector or mCherry. Orange arrows indicate CD31⁺ endothelial blood vessels and blue arrows show PAS⁺/CD31⁻ channels. The purple arrows indicate mCherry-positive tumour cells adjacent to PAS⁺ channels (green scale bars = 100 μm, grey scale bars = 50 μm). b, PAS/CD31 (left) and PAS/mCherry (right) staining of serially sectioned primary tumours resulting from orthotopic injection of a pool of the 23 clones, in which the 4T1-T clonal line constitutively expresses mCherry. Orange arrows indicate CD31⁺ endothelial blood vessels and blue arrows show PAS⁺/CD31⁻ channels. The purple arrows indicate mCherry-positive tumour cells adjacent to PAS⁺ channels (green scale bars = 100 μm, grey scale bars = 50 μm).