TOP3A and osteosarcoma: Previous studies have reported that various pathogenic variants of TOP3A lead to the instability of mitochondrial and nuclear genomes in different clinic disorders, including Bloom syndrome-like disorder, pediatric osteosarcomas and adult-onset mitochondrial disease (de Nonneville et al, 2022; Erdinc et al, 2023; Jiang et al, 2021; Martin et al, 2018; Primiano et al, 2022).