Lymphatic endothelial cells contribute to blood vessel formation in tumours

Using multicolor lineage tracing, in vivo time-lapse imaging and single cell transcriptional profiling in a mouse glioma model, we identify tumour blood endothelial cells carrying a Csf1r lineage trace. These Csf1r lineage endothelial cells (CLECs) form up to 10% of the tumour vasculature and express endothelial cell markers as well as a unique set of genes that can also be found in single cell transcriptome data of tumour endothelium from various human tumours. The transcriptomes of 768 single cells were sequenced (scRNAseq) after FACS sorting.