A targeting construct was designed to insert a creERT2 fusion gene (a Cre recombinase fused to a human estrogen receptor ligand binding domain) followed by a frt-flanked neomycin resistance (neo) cassette, just downstream of the start codon of the MAS-related GPR, member D (Mrgprd) gene. Breeding to B6.129S4-Gt(ROSA)26Sor/J (Stock No. 007844) removed the neo cassette. (J:245897)