EZH2 and neoplasm: Decreased PD‐L1 expression in the tumor environment after USP22 knockdown was found and the upregulation effects of PD‐L1 and USP22 induced by Taz or immunotherapy were also attenuated (Figure 6B,E,F), which suggested that USP22 is involved in EZH2‐mediated regulation of PD‐L1 expression.