An FRT flanked neo cassette and a loxP site were inserted in intron 5. A second loxP site was inserted in intron 6. Exon 6 which encodes part of theFERM domain is thus flanked by loxP sites. Both 145 and 125 kDa protein isoforms were lost as a result of conditional cre expression to excise exon 6 (as determined by immunoblotting.) (J:173383)