Considering the above-described reports, we decided (i) to evaluate whether immobilization of LL-37 peptide on the magnetic surface might alter the biological activity of LL-37 peptide from protumorigenic to anti-neoplastic, (ii) to assess if cathelicidin-mimicking ceragenin CSA-13 and its magnetic counterpart, MNP@CSA-13 composed of MNPs functionalized with CSA-13, exert anti-tumorigenic activity against breast cancer cells, and (iii) to investigate whether possible anti-cancer activity is determined by the same mechanism of action, as presented previously for colon cancer cells. This evidence concerns the gene CAMP and breast cancer.