Fig. 1
From: Nanomaterials in tumor immunotherapy: new strategies and challenges
The basic conditions of tumor microenvironment. Tumor microenvironment consists of tumor cells, tumor-associated fibroblasts, tumor-associated macrophages (TAM), Treg cells, CD8 + T cells, M1 macrophages, M2 macrophages, VEGF, cytokines and other related immune cells, all of them collectively contribute to tumor invasion and metastasis