The Fgfr2-IIIc coding sequence was cloned into a vector containing a floxed cassette with a PGK-Neo selection marker and a tpA transcriptional stop sequence. By homologous recombination, this construct was inserted into the locus. Upon Cre-mediated excision of the selection cassette/stop sequence, the IIIc isoform is transcribed under control of the Gt(ROSA)26Sor promoter. (J:261451)