GNRH1 and breast cancer: The replacement of 6Gly by D-amino acids in human GnRH-I provides superagonists like the GnRH-I derivatives buserelin [6D-Ser(t-Bu), 9Pro-EA], goserelin [6D-Ser(t-Bu), 10Azagly-NH2], leuprolide [6D-Leu, 9Pro-EA] and triporelin [6D-Trp], which are used as pharmaceutical peptides to treat inter alia hormone dependent prostate and/or breast cancer [7].