FGFR4 and sarcoma: Whereas the inhibition of tyrosine phosphorylation of PDGFR and ERBB family members was a common event in roneparstat-treated cells from the different sarcoma histotypes, the drug interference on the activation of other receptors (i.e. IGF1R, FGFR4) was found to occur in a cell line-specific way (Figure 1).