Sequencing revealed a 24-bp insertion occurring in the promotor, −377 ∼−354, of PRL (GenBank accession no. AB011434). A single nucleotide polymorphism (SNP), A9026G (GenBank accession no. AY237377), in exon 3 of PRLR was also detected, which led to a nucleotide transition in the 5′-untranslated region (5′-UTR) of PRLR cDNA.TwoSNP,T14771CandG14820A(GenBankaccession no. AY237376), were detected in exon 6 of the PRLR.