“…Primary tumor cells and host cells secrete various factors that support CSC survival and dissemination, creating a pre-metastatic microenvironment (Kaplan et al, 2005;Chin and Wang, 2016;Sivan et al, 2019). Further, CSCs can modulate angiogenesis by producing proangiogenic factors such as VEGFA (Chand et al, 2016) to induce unregulated tumor angiogenesis and metastasis (Carmeliet and Jain, 2011;Treps et al, 2017;Sun et al, 2020; Figure 3 and Table 1). Here, malignant alterations of the BM niche in hematologic tumors, primary bone tumors and bone metastasis are highlighted.…”