A new research study has shown that chondroitin sulfate, a dietary supplement taken for osteoarthritis, selectively promotes growth of a specific type of melanoma cell in mice. Approximately half of melanoma cells have the B-raf gene mutation known as V600E. The research team confirmed that chondroitin sulfate increases growth of melanoma cells with the mutation but other melanoma cells were unaffected. The findings have not been confirmed in human studies but oncologists and individuals with melanoma should still be aware of the risk of taking the supplement. The study was published in Molecular Cell. Read more.