Given appropriate conditions, a peptide comprising an RGD recognition motif for targeting integrins (which are highly expressed in renal cell carcinoma (RCC)), a cleavage site for matrix metalloproteinases (MMP)-2/9 (which are typically overexpressed in the tumor microenvironment), and an NIR moiety (Cy) for signaling, self-assembled to nanofibers in solution (Figure 18) [188]. The gene discussed is MMP2; the disease is renal cell carcinoma.