PDCD1 and neoplasm: This result suggested that, in combination with cabozantinib, chidamide may be potently effective, not inferior to anti-PD-1 antibody, as shown in Figure 1C. Similar results were also observed in the regorafenib treatment groups; anti-PD-1 antibody combined with regorafenib plus chidamide-k30 was more effective in inhibiting tumor growth than anti-PD-1 antibody combined with regorafenib.