TGFB1 and breast cancer: In BC settings, there are some cytokines associated with the development, differentiation, and expansion of MDSCs, including granulocyte colony-stimulating (G-CSF), macrophage colony-stimulating factor (M-CSF), GM-CSF, IL-6, IL-1β, macrophage migration inhibitory factor (MIF), and TGFβ [169,170,171].