Villarreal et al. [34] performed genome-wide R-loop mapping of DNA/RNA hybrid loci regulated by DDX5, XRN2, and PRMT5, and observed hundreds to thousands of R-loop gains and losses at transcribed loci in DDX5-, XRN2-, and PRMT5-deficient human osteosarcoma U2OS cells [34]. Here, DDX5 is linked to osteosarcoma.