A targeting vector was designed to insert a single loxP site upstream, and a loxP and FRT site flanked neomycin resistance gene cassette downstream of the locus. The neo cassette was removed by flpe-mediated recombination. A null allele was created by removing the floxed locus through cre-mediated recombination. Absence of transcripts from this locus was confirmed by miR-seq and RNA-seq.