MMP2 and neoplasm: The TRAIL-ATNC construct and the expected trimer display are depicted in Fig. 1A. IL4rP (CRKRLDRNC)43 was ligated to the C-terminal end as a tumor-targeting peptide moiety, and a matrix metalloproteinase-2 (MMP2) cleavage site (GPLGLAG)55 was inserted in the middle of the flexible linker between IL4rP and the ferritin carrier to prevent unwanted IL4 receptor-mediated endocytosis after targeting.