Overexpression of RFWD3 promotes tumor growth with increased myeloid‐derived suppressor cells (MDSCs), while inhibition of RFWD3 increases intracellular dsDNA levels, activates the STING‐IFN signaling, decreases MDSCs, and enhances the efficacy of PD‐L1 blockade in murine NSCLC models. Here, STING1 is linked to neoplasm.