GAPDH and osteosarcoma: The results of RT-qPCR analysis demonstrated that the RNA expression level of EBLN3P was expressed at higher levels in four osteosarcoma cell lines (Saos2, 143B, MG63 and U2OS) compared with those in the normal human fetal osteoblast cell line, while the RNA expression level of miR-224-5p exhibited the opposite trend (normalized to GAPDH, Fig. 1A).