PTGDR and osteosarcoma: The oncogenic lncRNA AFAP1-AS1 (actin fiber-associated protein 1 antisense RNA 1) has been proposed as a promising therapeutic target in osteosarcoma as it is found to be overexpressed and promoting the epithelial-mesenchymal transition of osteosarcoma through RhoC/ROCK1/p38MAPK/Twist1 signaling pathway (Shi et al., 2018).