First, although the tip cell phenotype represents only a minor part of freshly isolated human (T)ECs (<10%) in lung cancer, tip cells (1) are restricted to TECs (99.3% of human tip cells originate from TECs; Fig. 1c) and (2) are the phenotype that is most sensitive to anti-VEGF treatment in the murine LLC model8, underscoring their relevance in pathological angiogenesis. Here, VEGFA is linked to lung cancer.