The endothelium has multiple functions from maintaining vascular homeostasis, providing nutrition and oxygen to tissues, to evocating inflammation, under adverse conditions, and determining endo-thelial barrier disruption resulting in dysfunction. Endothelial dysfunction represents the typical condition associated with the pathogenesis of all the diseases of cardiovascular system, as well as of diseases of all the other human body’s systems, also including sepsis, acute respiratory distress syn-drome and COVID-19 respiratory distress. Such evidence is leading to identifying potential bi-omarkers and therapeutic targets for preserving, reverting, or restoring endothelium integrity and functionality by early treating its dysfunction. Here, it stresses some strategies for achieving these goals, even if diverse challenges exist and require a significant bench work associated with an in-creased number of clinical studies.