PECAM1 and neoplasm: Importantly, our results further revealed that upregulating MFSD4A-AS1 increased, while silencing MFSD4A-AS1 reduced the density of lymphatic or blood vessel (LBV) in tumor tissues, as demonstrated by the CD31+ and PDPN+ LBV per mm2 in tumor sections (Fig. 3A, B, C, D, E and F).