CCND1 and osteosarcoma: As shown in Figure 2B, in osteosarcoma, NNT-AS1 can sponge miR-320a and up-regulate the expression of β-catenin, RUNX2, p-AKT, insulin-like growth factor type 1 receptor (IGF1R), MYC, cyclin D1, and MMP-13, thereby promoting osteosarcoma cell growth and tumor development [28].