IL1B and chondrosarcoma: The more limited effect of unmodified HA in the current study could be associated with differences between the unmodified HA preparations evaluated, but also in cell type (human OA, human RA, chondrosarcoma cell lines), dose of HA used (e.g. in some publications effects seen only with >2 mg/ml), and pre-incubation prior to IL-1 stimulation variably used in previous studies.