Lysine codons 98 (AAA), 117 (AAG), 136 (AAG), 160 (AAG), and 161 (AAG) were changed to arginine (p.K98R + p.K117R + p.K136R + p.K160R + p.K161R). Cre-mediated recombination removed the loxP site flanked neomycin resistance gene cassette that was inserted into intron 4. (J:314680)