A knockdown vector was constructed with a conditional Rnu6 (U6) promoter (disrupted by insertion of a loxP-flanked neo cassette) driving short hairpin RNA specific for mouse Bccip. The construct was injected into FVB/N fertilized oocytes. Two founder lines (4 and 13) were generated. Line 4 was analyzed to a greater extent. Cre recombination will excise the floxed neo cassette, reconstitutng activity of the Rnu6 promoter and allowing transcription of the anti-Bccip shRNA resulting in RNA interference of the Bccip gene.