The transgene based on murine BAC clone (RP23-343C17) containing the sequence between the proglucagon start codon in exon 2 and stop codon in exon 6 was used to express iCreERT2 under the control of the proglucagon promoter. Initially, two transgenic lines 9 and 17 were established both with an estimated transgene copy number of one. The initial characterization did not reveal any differences and line 9 was used in the study.