GNRH1 and melanoma: Our recent results on melanoma cells indicated that in the case of the GnRH-III conjugate modified with butyrated 4Lys GnRH-III[4 Lys(Bu),8Lys(Dau=Aoa)]), its antitumor effect was rather attributed to apoptotic activity, in contrast to the GnRH-III[8Lys(Dau=Aoa)]-possessing 4Ser, where the cell cycle blocking effect (arrest in the G2/M phase) was shown to be more prominent [22].