CTCF and osteosarcoma: Macrophage-derived lncRNA Livr-AS1 (Zhang et al., 2021), miRNA-221–3p (Liu et al., 2021b), let-7a (Yan et al., 2023); lncRNA OIP5-AS1 (Li et al., 2021a) CTCF (Zhan et al., 2022) derived from osteosarcoma cells can all participate in the progression of osteosarcoma, as shown in Figure 6.