PECAM1 and lung cancer: Notably, the association between increased mRNA nucleolin expression and more advanced disease stages (for lung adenocarcinoma, Figure S1), along with the prognostic value arising from its high expression in CD31-positive tumor endothelial cells (poor survival) [38], and in the cytoplasm/membrane (unfavorable survival) [32,43], emphasized the importance of gaining a better understanding of the overall role of nucleolin in lung cancer progression.