HMOX1 and visceral leishmaniasis: Furthermore, cobalt protoporphyrin (CoPP), an HO-1 inductor, increases Leishmania infantum chagasi burden in human and mouse macrophages, and HO-1 was associated with visceral leishmaniasis (VL) disease susceptibility as the VL patients presented higher systemic concentrations of HO-1 than healthy individuals [148].