MMP9 and neoplasm: For example, gH625 (HGLASTLTRWAHYNALIRAF), a membranotropic peptide, was derived from herpes simplex virus type I by Stefania Galdiero’s group [13] and utilized in delivering self-assembled peptide-based nanofibers (NFs) with a matrix metalloproteinase-9 (MMP-9)-responsive sequence to enhance the penetration efficiency and tumor-triggered cleavage of doxorubicin in triple-negative breast cancer cells [14].