STAT3 and breast cancer: Zhang et al. showed that MDSCs from fresh BC tissues displayed high levels of suppressive molecules, such as Arg1, iNOS, ROS, PD-L1, and P-STAT3, and stronger suppression of T-cell proliferation, and further identified the CXCL2/MIF-CXCR2 axis as an important mediator in MDSC recruitment and as a potential therapeutic target in BC patients [151].