A conditional ready (floxed) allele was created by removing the FRT-flanked lacZ sequence, loxP site, neomycin cassette under the control of the human beta-actin promoter and SV40 polyA via flp-mediated recombination from the KO first allele generated using EUCOMM vector (PG00126_Z_3_B08), leaving exon 5 flanked by loxP sites. (J:227476, J:235694)