CSF2 and metastatic colorectal cancer: In contrast, patients with metastatic colorectal cancer treated with a combined chemoimmunotherapy containing gemcitabine and FOLFOX-4 (oxaliplatin, fluorouracil, and folinic acid) polychemotherapy followed by the subcutaneous administration of GM-CSF and low-dose IL-2 showed clinical objective responses in the majority of patients associated with a significant reduction in CD4+CD25highFOXP3+ Treg cells as reported by Correale et al.[44], [45].