SPON1 and chondrosarcoma: Interestingly, SPON1 has been shown to be upregulated in several cancers, including neuroblastoma and chondrosarcoma, and it has also been found to have a role in promoting neuroblastoma by leading high IL-6 expression through the MEKK/p38 MAPK/NF-κB–dependent pathway (74, 75).