SNRPD2 and hepatocellular carcinoma: To assess DDR induction, we analyzed the formation of phosphorylated H2A.X (γH2A.X) foci as a marker for double-stranded DNA breaks (DSBs) and identified a significant increase in γH2A.X-positive cells after SNRPD2 knockdown in HCC cells (Fig. 3e–g, Supplementary Fig. 3b), which further supports our conclusion that SmD2 loss induces DDR.