Our previous studies identified that miR‐21 was increased in ECs in response to tumour necrosis factor alpha (TNF‐α) and 4‐hydroxynonenal (4‐HNE) stimulation and miR‐21–mediated DDAH1‐ADMA‐eNOS activation plays a critical role in mediating DMY’s protective effects on TNF‐α–induced endothelial dysfunction.20, 23. Here, TNF is linked to endothelial dysfunction.