Back-to-back papers in the June 22, 2023, issue of Nature have identified separate molecular mechanisms underlying sex-specific cancer outcomes. Researchers from The University of Texas MD Anderson Cancer Center showed that increased expression of the epigenetic enzyme KDM5D, which is located on the Y chromosome, contributed to cancer progression in KRAS-mutated tumors. In the same issue of Nature, a team from Cedars-Sinai reported new insights into the consequences of losing the entire Y chromosome.