Our clinical observation that increased serum Ang2 in human scrub typhus patients correlates with O. tsutsugamushi-specific antibody titers demonstrates the utility of Ang2 as a pathogenic biomarker, and highlights the potential of use Ang2- or Tie2-targeted therapies for severe scrub typhus, as in patients with severe sepsis [32, 33] and malaria [58]. Here, ANGPT2 is linked to scrub typhus.