VEGFA and lung cancer: Similar autocrine signaling mediated modulation of enzymes by VEGF was previously observed in A549 lung cancer cells,35 vascular smooth muscle cells,23 and chondrocytes.36 Both paracrine and autocrine signaling play a role in tumor microenvironment changes mediated by VEGF as demonstrated in a study where suppressing VEGF decreased metastasis via disrupting both the autocrine and paracrine signaling loops of VEGF.37