The invasion of cancer cells to the perivascular environment relies on their motility, in which motility-involving molecules such as ARP2/3, L1CAM, serpins, CD44, CDC42, CXCR4, epidermal growth factor receptor (EGFR), as well as Wnt7 signaling, are critical players (16, 20, 25, 26, 43, 52, 64, 73, 74, 94–96) (Figure 6A). Here, CDC42 is linked to cancer.