However, in this study, the expression levels of PD-L1, which is expressed on the surface of myeloid-derived suppressor cells: the precursor cells of M1 and M2 macrophages, and tumor-associated macrophages: a collective term for macrophages within the TME [23, 24], as well as HIF-1α, which is expressed in the nucleus of M1 macrophages and an activator of M2 macrophages [17, 21], increased during treatment. The gene discussed is HIF1A; the disease is neoplasm.