IL10 and neoplasm: Tumor-infiltrating myeloid-derived suppressor cells (MDSCs) can generate de novo regulatory T cells (Tregs) from naive CD4+ T cells and augment existing FOXP3+ Tregs through cell–cell interactions and soluble factors (e.g., indoleamine 2,3-dioxygenase, transforming growth factor-beta, interleukin-10) [59,60,67].