CSF3 and cancer: As tumor-derived G-CSF has been established as the principal driver of leukocytosis associated with many types of cancer [23], we posited that DOX and Nano-DOX might have downregulated G-CFS expression in 4T1 cells thus accounting for the abated granulocytosis (Fig. 3a) and tissue MDSCs infiltration (Fig. 7a, b).