Although PD‐L1 Ab and JAK/Stat3 inhibitors both affect PD‐L1, we speculate that their molecular mechanisms are different; the PD‐L1 Ab is expected to block the PD‐L1/PD‐1 interaction between tumor and NK cells, while the JAK/Stat3 inhibitors will contribute to lowering the PD‐L1 ligands in tumor cells, as we noted that the use of PD‐L1 Ab did not reduce the PD‐L1 level in tumor cells (data not shown). Here, STAT3 is linked to neoplasm.