As a key enzyme in the non‐homologous end joining (NHEJ) pathway of double strand break (DSB), DNA‐PK is significantly expressed in breast cancer including TNBC and certain cancer types (non‐small cell lung cancer, prostate cancer, and liver cancer), and is intimately connected to the dreadful prognosis of breast cancer.21, 22. This evidence concerns the gene PRKDC and cancer.