COASY and breast cancer: We found that COASY knockdown similarly triggered multinucleation in multiple cancer cell lines, including A549 (lung adenocarcinoma) (Fig. 1c), MDA-MB-231 (breast cancer) (Supplementary Fig. 1f), PANC-1 (pancreatic cancer) (Supplementary Fig. 1g), and non-cancerous cell line ARPE-19 (human retina) (Supplementary Fig. 1h).