Solid tumor development consists of a series of stages during which cells undergo genetic and phenotypic alterations that allow cancer cells to evade normal regulation and to finally colonize distant sites in the body. In this issue of The American Journal of Pathology, Petty et al report that expression of a relatively understudied protein called migration-inducing protein 7 (MIG7 or Mig-7) facilitates tumor cell dissemination by increasing invasion and promoting the process of vasculogenic mimicry.1 Vessels that form during tumorigenesis are usually lined by an endothelium, but abnormal vessel development in which cancer cells directly line vessels or blood channels within tumors have been described and termed vasculogenic mimicry.2,3,4,5 One of the earliest descriptions of these tumor-lined vasculogenic channels was by Willis, who stated in 1948 that “in rapidly growing tumors, [vessels] consist of little more than irregular channels lined by endothelium only or by naked tumor cells.”2 These structures have also been noted by vascular biologists as a category of blood vessel or “blood channels lacking an endothelial lining” in which “blood percolates around and between tumor cell chords” that occur in tumors.3 Renewed interest in these structures occurred after publication of a manuscript in 1999 by a group led by Mary Hendrix, which reported tumor lined-blood channels in areas of looping extracellular matrix in uveal and cutaneous melanomas.4 Since then, the slow process of unraveling the genes, signaling pathways, and pathophysiological significance of these structures has been underway.6,7,8,9,10 This remains a very important area of research with significant implication for therapeutic development.11,12