Fig. 2
From: Regulation and signaling pathways in cancer stem cells: implications for targeted therapy for cancer
Tumor microenvironment control of CSCs. Various nontumor cells, including stromal cells and immune cells, and metabolic control which exist in the tumor microenvironment participate in CSC characteristic maintenance, CSC-associated tumor metastasis and CSC-associated therapy resistance. Cancer-associated fibroblasts (CAFs) are the most representative stromal cells, and tumor-associated macrophages (TAMs) are the most essential immune cells. They contribute to CSC characteristics maintenance by secreting particular cytokines. The detailed cytokines and corresponding factors that these cytokines influenced were all shown in the yellow boxes. In term of metabolic control which could participate in CSC characteristic maintenance, glycolysis, glutaminolysis, lipogenesis and hypoxia-inducible factors are the most representative four parts (red boxes)