TGFB1 and neoplasm: This may partly be due to the immunosuppressive status in the TME mediated by negative immune cells [such as tumor-associated macrophages (TAMs), T-regulation cells (Tregs), and myeloid-derived suppressor cells (MDSCs)] and immune inhibitory cytokines (such as IL-10, TGF-β, IL-35, and IL-27), and the poor tumor targeting and penetration of tumor-reactive immune cells (22, 23).