ANGPT1 and cancer: The effect of CM on Tie2 induction on MDA-MB231, BT474 and HUVEC was mediated by Ang-1 because Ang-1 knockdown (Supplementary Figure S3B and S3C) in the fibroblasts led to a remarkable reduction of Tie2 phosphorylation by CM to levels observed in untreated cancer cells (Figure 5C).