Glioblastoma accounts for 50.1 percent of all primary malignant brain tumours. Tumour stem cells play a key role in treatment resistance and tumour recurrence, as they are capable of self-renewal, have tumour-initiating capabilities, and are adaptable to environmental stress, including chemotherapy. The aim of this study was to generate variants of an already published peptide that specifically targets the Cadherin 2 membrane proteins and receptors found on glioblastoma stem cells, which may improve diagnostics and therapeutic targeting. The most important result of the study so far is the structure-activity relationship of the peptide – daunomycin conjugates based on the CD spectroscopy analysis and MTT assays.