Peptides Containing The Sequence (tyr-ala-asp-ala-ile-phe-tyr -asn-ser Tyr-arg-lys-val -leu-gly-gln-leu-ser- Ala-arg-lys-leu-leu- Gln-asp Ile-met-a-arg- Gln-gln-gly-glu-b-asn- Gln-glu-c-gly- -ala-d-e Arg-leu-nh) With A Being Ser Or Asn, B Being Ser Or Arg, C Being Arg Or Gln, D Being Arg Or Lys, And E Being Ala, Val, Or Phe, E.g., Somatoliberin (gonadotropin Releasing Factor) (c07k-99/00f) Patents (Class 930/DIG559)