Inhibition of FGFR3 reduces viability of FGFR3-expressing KMS11 and KMS18 cells. (A) FGFR3-expressing cells and (B) myeloma cell lines lacking FGFR3 expression were cultured for 48 hours in the presence of aFGF/heparin and increasing concentrations of PD173074. The number of viable cells was assessed by MTT assay. Viability of untreated cells was defined as 100%. Values represent mean ± SD of 4 independent experiments.