A 36,241 bp genomic fragment spanning exons 18 - 31 was replaced with a PGK-neo cassette via homologous recombination. This resulted in removal of part of the IQ2 and all of the IQ3, IQ4, and GRD motifs. QRT-PCR confirmed the absence of transcript in hepatocytes and immunoblot analysis confirmed the absence of protein in liver, spleen, heart, and kidney lysates. Only in the liver was a modest increase in Iqgap1 expression detected. QRT-PCR analysis did not detect any change in F2rl2 (coding sequence contained within intron 13 of Iqgap2) expression.