Inactivation of FGFR3 induces differentiation of KMS11 and KMS18 cells. KMS11 and KMS18 cells were exposed to vehicle or 50 nM PD173074 for 4 and 10 days, respectively. (A) Wright-Giemsa stain of KMS11 cytospin and hematoxylin and eosin-stained section of KMS18 clot sections (original magnification, × 400). Approximately 60% of KMS11 and 40% of KMS18 cells demonstrated a more mature morphology as demonstrated in the inset (original magnification, × 400). (B) CD138 (left) and CD31 (right) expression for vehicle (dotted lines) and PD173074 treated KMS11 cells (solid lines). Filled histogram represents isotype control. (C) ELISA detection of κ and λ secretion of KMS11 (▦) and KMS18 (▪) cells, respectively. Values represent mean ± SD μg/mL from 8 and 6 independent experiments, respectively. No effect of PD173074 treatment was noted in 8226 tumors similarly treated (data not shown).