To explore this possible role, we examined the associations of both common and rare genetic variants in TTN and BAG3 with the risk of late-onset CCM among long-term survivors of childhood cancer from the 2 largest pediatric cancer survivor cohorts in North America: the St Jude Lifetime Cohort (SJLIFE) and the Childhood Cancer Survivor Study (CCSS). This evidence concerns the gene TTN and childhood malignant neoplasm.