EDN1 and myalgic encephalomeyelitis/chronic fatigue syndrome: Specific endothelial markers that can be indicative of their senescence have been shown to be increased in ME/CFS and long COVID cohorts, including ET-1 [29, 31, 43, 44, 100, 101], VEGF-A [102], VCAM-1 [44, 100], ICAM-1 [31, 103], PAI-1 [44], IL-8 [31], MCP-1 [31] and FGF-2 [102].