In the Hdac5 knockdown group, anti-PD-1 treatment dramatically increased the tumor infiltration of CD45+CD8+ and CD45+CD4+ T cells as well as decreased the levels of CD11b+Gr1+ myeloid cells and CD4+Foxp3+ Treg cells in tumors (Figure S5E; Figure S6E-F). Here, HDAC5 is linked to neoplasm.