TEK and neoplasm: Albeit staining tumor tissues with anti‐P‐Tie2 antibodies has technical limitations, we found that P‐Tie2 and Angpt2 co‐localize in the tumors, whereas in adjacent non‐tumor areas Angpt2‐positive pituitary cells do not express P‐Tie2 (Fig EV3; Appendix Fig S10A and B).