Rr167^tm1.1Masar

A 445 bp deletion in intron 2 of Il4 was engineered by replacing the sequence with a loxP site flanked neomycin resistance gene cassette. The neo cassette was removed through subsequent cre-mediated recombination, leaving an allele lacking the 220 bp highly conserved intron enhancer (hcIE). Expression from this allele is greatly reduced compared to wild-type. (J:240744)