Although the majority of lncRNAs enhances endothelial dysfunction in diabetes, some of them may have a protective function: for example, the lncRNA-MEG3 facilitates the activation of PI3K/AKT signalling in ECs [119]; accordingly, its expression is down-regulated in retinal vessel of STZ-induced diabetic mice and in ECs exposed to hyperglycaemic and oxidative stress conditions, while MEG3 knockdown associates with capillary degeneration and microvascular leakage, worsening retinal vessel dysfunction in diabetic mice [119]. The gene discussed is MEG3; the disease is diabetes mellitus.