A cassette containing the chicken beta actin promoter CAG driving the expression of a floxed neo-STOP cassette followed by cDNA encoding human MIRN 17, 18a, 19a, 20a, 19b and 92 plus an frt-flanked IRES-EGFP cassette and a poly-adenylation site were inserted into the ROSA locus. This allele is also a knockin allele that allows for expression of the human MIRNs contained within it following the cre-mediated removal of the neo-STOP cassette. (J:133215)