Abstract: OBJECTIVE To explore the expressions of stimulator of interferon genes (STING), TANK-binding kinase 1 (TBK1) and signal transducer and activator of transcription 6 (STAT6) in peripheral blood of modified radical mastectomy patients with postoperative infection. METHODS Totally 90 breast cancer patients who were treated in the Central People's Hospital of Zhanjiang from Feb 2020 to Feb 2021 were enrolled in the study and were divided into the infection group with 27 cases and the non-infection group with 63 cases according to the occurrence of postoperative incision infection. The distribution of pathogens was analyzed, the relative expression levels of STING, TBK1 and STAT6 mRNA in peripheral blood were detected by polymerase chain reaction (PCR) before the surgery. The levels of inflammatory factors procalcitonin (PCT), C-reactive protein (PCT) and interleukin-6(IL-6) were compared between the two groups after the surgery for 5 days. The values of STING, TBK1 and STAT6 in prediction of postoperative infection were analyzed by receiver operating characteristic (ROC) curve. RESULTS Totally 33 strains of pathogens were isolated from 27 patients with postoperative incision infection, 21 (63.64%) of which were gram-positive bacteria, and 12 (36.36%) were gram-negative bacteria. The relative expression levels of peripheral blood STING, TBK1, STAT6 mRNA and the levels of CRP, PCT and IL-6 were higher in the infection group than in the non-infection group (P＜0.05). ROC curve analysis showed that the areas under curves (AUCs) of the peripheral blood STING, TBK1 and STAT6 were respectively 0.933, 0.909 and 0.894 in prediction of the postoperative incision infection. CONCLUSION The modified radical mastectomy patients with postoperative incision infection show abnormal expressions of peripheral blood STING, TBK1 and STAT6, which have high efficiencies in prediction of the infection.