It has been reported that STAT3 is also involved in expansion of MDSCs (Wu et al., 2011), activation of CD14+HLA-DRnegative/low MDSCs in blood of cancer patients (Poschke et al., 2010), expression of immunosuppressive arginase-1 in human MDSCs (Vasquez-Dunddel et al., 2013), survival of Tregs (Pallandre et al., 2007), and anti-tumor activity of CD8+ T cells (Kujawski et al., 2010). This evidence concerns the gene STAT3 and cancer.