The FRT cassette in TI{TI}simaFRT(E2-6) has been excised, deleting sima exons 2 through 6, which results in an amorphic allele. A single FRT site remains at the location of the deleted sequence, followed by the loxP cassette encoding the Disc\RFPmCherry.3xP3 marker (this loxP cassette was present in TI{TI}simaFRT(E2-6)).