In addition to the transcriptional regulation, protein stability regulation is also an important way for tumor cells to up‐regulate PD‐L1 level, in which the ubiquitin degradation mediated by ubiquitin proteasome system is critical.[30, 31] Although our study has demonstrated that SRC‐1 transcriptionally regulates PD‐L1 expression through STAT3‐IRF1 axis, whether PD‐L1 is post‐transcriptionally regulated by SRC‐1 is unclear. This evidence concerns the gene IRF1 and neoplasm.