DHX9 and ovarian cancer: A recent study noted that elevated R-loops and subsequent DNA damage, senescence and cell death will suppress tumor cells in BRCA1/2-mutant breast and ovarian cancer, and the detailed mechanism is related to the DNA damage response protein Ring Finger Protein 168 (RNF168) deficiency, which disrupts the recruitment of DExH-Box Helicase 9 (DHX9) at R-loop genome loci and resolution of R-loops [104] (Fig. 4A).