SLFN11 and cancer: Given that SLFN11 is a key responder to replication stress, its expression status is being actively investigated as a biomarker for drug selection and prognosis in cancer therapy with broadly used DNA-damaging agents (DDAs), including topoisomerase I (TOP1) inhibitors (topotecan, irinotecan, and indotecan), TOP2 inhibitors (etoposide, doxorubicin, and epirubicin), alkylating and crosslinking agents (cyclophosphamide, temozolomide, cisplatin, carboplatin, and oxaliplatin), and DNA synthesis inhibitors (5-fluorouracil, gemcitabine, cytarabine, and hydroxyurea)12,52–54 (Fig. 5A).