SPRY4 and osteosarcoma: Furthermore, we observed that osteosarcoma cells with increased Spry3 do not necessarily express high or low Spry1 protein, but interestingly, in comparison with an earlier report investigating Spry2 and Spry4 in osteosarcoma-derived cell lines, it was revealed that MG63 and 143B, the only cell lines with prominent Spry1 levels, also showed high levels of Spry2 and Spry4 [34].