FOXP3 and esophageal squamous cell carcinoma: Conversely, in the ESCC TME, IL-17 [mainly produced by CD4+ Foxp3- Th17 cells (17)] stimulates tumor cells chemokine (CXCL2 and CXCL3) production, causing accumulation and activation of myeloperoxidase+ TANs, which increase their killing capacity by releasing cytotoxic molecules, including IFN-γ, reactive oxygen species (ROS), and TNF-related apoptosis-inducing ligand, and predict favorable prognosis in ESCC patients (94).