FOXD2 and osteosarcoma: Combining these differentially expressed PRLs with the corresponding clinical information from TARGET, 13 lncRNAs related to the prognosis of osteosarcoma were initially screened (Fig. 6B), and 9 key lncRNAs (FOXD2-AS1, AC010894.2, AC018904.1, AL035446.1, UNC5B-AS1, BX322562.1, SENCR, AC090559.1, AC016596.1) were further determined through the LASSO regression analysis (Fig. 6C, D, E, Additional file 1: Table S2).