The albumin-binding domain (ABD) with a site for its cleavage by tumor proteases was inserted in the structure of modular nanotransporters (MNTs), chimeric proteins for the delivery of anticancer drugs into the nuclei of cancer cells. The effectiveness of this cleavage was tested in both variants of created construct: "pure" ABD-MNT and the complex with albumin. The introduction of the ABD module into MNTs had no effect on the binding of MNT with receptors on the surface of the target cancer cells and on the preferential accumulation of MNTs in the nuclei of these cells. The use of thermophoresis allowed us to determine the equilibrium dissociation constants of the ABD-MNT complex with bovine and human serum albumins.