SERPINB1 and neoplasm: For instance, overexpression of neuronal cell adhesion molecule L1 (L1CAM), serpin B1, actin-related protein 2/3 complex (ARP2/3), runt-related transcription factor-1 (RUNX1), and integrin α5β1 (ITGA5) in tumor cells facilitates vessel co-option by promoting the epithelial-mesenchymal transition (EMT) and motility of tumor cells (13–16).