While it is well-established that PMN-MDSCs have immunosuppressive functions [1,26], our recent study showed that PMN-MDSCs can be permissive of anti-tumor immunity under certain circumstances [27], consistent with a report showing that PMN-MDSC in ceralasertib, an ATR inhibitor, treated tumor-bearing mice were less suppressive against CD8 T cells, which was associated with up-regulation of type I IFN signature [28]. This evidence concerns the gene ATR and neoplasm.