Notch signalling was inhibited significantly in myeloid-derived suppressor cells (MDSCs) in tumour-bearing mice.

MDSCs without Notch signalling were down-regulated their immunosuppressive activity.

The blockage of Notch signalling in MDSCs reduced the impairment on dendritic cell development.

Notch signalling inhibited the generation of polymorphonuclear-MDSCs but improved the production of mononuclear MDSCs both in vitro and in vivo.

Stat3 pathway mediated the Notch-signalling effects on MDSCs.