TA-MSCs from tumors like osteosarcoma [219], breast cancer [220], ameloblastoma [68], gastric cancer [211, 221], glioma [38, 98], and ovarian carcinoma [61, 179], promote tumor cell stemness by releasing factors such as IL-6, IL-15, R-spondin, exosomal miR-1587, BMP, and LIF. This evidence concerns the gene IL15 and central nervous system cancer.