Tovalidate the applicability of using GFPp_FGF1 oligomers as cancerprobes and drug carriers in targeted therapy of cancers with aberrantFGFR1, we selected a trimeric variant from generated GFPp_FGF1 oligomersand further engineered it by introducing FGF1-stabilizing mutationsand by incorporating the cytotoxic drug monomethyl auristatin E (MMAE)in a site-specific manner. This evidence concerns the gene FGF1 and cancer.