Activation of PLCγ and STAT3 in tumors of EμSR-FGFR3 TDII transgenic mice. Spleen samples from a healthy normal FVB mouse were included as a control. (A) FGFR3 TDII is expressed and constitutively activated in the tumor tissues of EμSR-FGFR3 TDII transgenic mice A.5652 and A.5653. Expression of FGFR3 TDII was detected by immunoblotting in lymph node cell lysates. The activating tyrosine-phosphorylated FGFR3 TDII was detected by an antibody specifically recognizing the 2 phosphorylated activation loop tyrosine residues in FGFRs. (B) PLCγ is hyperphosphorylated and activated in the tumor tissues by FGFR3 TDII in transgenic mice. (C-D) Elevated tyrosine phosphorylation of STAT3 and expression of Bcl-_XL in tumor tissues of FGFR3 TDII transgenic mice.