LyP-1 TFA, a cyclic nine-amino-acid peptide, exhibits selective binding to p32 receptors, which are overexpressed in a variety of tumor-associated cells [1].

Treatment with LyP-1 TFA for 8 weeks significantly reduces plaque formation and occupancy, accompanied by increased apoptotic rates in macrophages from hypoxic plaques, in comparison to a control peptide [1]. Additionally, 4T1 tumor-bearing BALB/C mice received intradermal injections of Cy5.5-labeled LyP-1 at 0.8 nmol into the forelimb proximal to the tumor at days 3, 7, 14, and 21 post-tumor cell inoculation. Fluorescence intensities were 1.02, 1.63, 2.04, and 4.52 times higher than the contralateral lymph nodes (LNs) at corresponding time points, with values of 0.024, 0.038, 0.048, and 0.106 × 10^6 photons/cm^2/sec. Cy5.5-LyP-1 prominently stained LNs and showed co-localization with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), indicating the lymphatic specificity of the peptide [1].