The observed poorer prognosis of PD-L1 negative or TIL-low TNBC tumors might be mediated through tumor-associated macrophages and immunosuppressive myeloid-derived suppressor cells, which are tumor promoting and involved in therapeutic resistance, angiogenesis, secretion of immunosuppressive mediators, such as TGF-β, and in inducing EMT [31–33]. Here, TGFB1 is linked to neoplasm.