In respect of potential clinical applications of the tested conjugates in the future, a table was prepared (Table 1) which helps to compare cytotoxic efficacy (IC50) of the 15 GnRH-based antitumor conjugates in 3 reference tumor cell lines representing the most frequent malignancies (breast cancer – MCF-7, colorectal adenocarcinoma – HT-29 and acute monocytic leukemia – MonoMac6). This evidence concerns the gene GNRH1 and breast cancer.