Perivascular niches go from simple forms represented by endothelial cells associated with Nestin+ and CD133+ cells, which condition angiogenesis and tumor growth [10], to more complicated niches that include astrocytes, fibroblasts, macrophages, pericytes, nonstem tumor cells, and microglia [9] with a complicated cross-talk [11]. Here, PROM1 is linked to neoplasm.