ANGPT2 and neoplasm: To prove that Angpt2 secreted by tumor cells is bioactive, we assessed cell proliferation by exposure of scRNA‐ (control) or siAngpt2‐transfected GH3 cells (to suppress endogenous Angpt2 secretion) to the serum‐free CM of primary rat NF‐PitNET cells, which predominantly express Angpt2 (Fig EV1).