RAC1 and osteosarcoma: To explore the specific molecular mechanism by which LRP1–SNRNP25 promotes the invasion and migration of osteosarcoma cells, we first examined the levels of proteins involved in invasion and migration, such as ERK/pERK and JNK/pJNK in the MAPK signaling pathway and Akt/pAkt in the PI3K/Akt signaling pathway, and cytoskeleton-, cell movement-, and cell adhesion-related proteins, such as FAK, MMPs, and Rac1, and the RhoA, by western blotting.