On the other hand, the results of in vitro studies showing that 5a can specifically bind αvβ6-/αvβ8+ cells (in an αvβ8-dependent manner) and the results of in vivo studies showing specific accumulation of 5a-IRDye in αvβ6-/αvβ8+ prostate tumors (TRAMP-C2 model) suggest that this peptide can also accumulate on cells expressing this integrin in tumors, such as carcinoma cells and infiltrating regulatory T cells 12, 23, 33. Here, C2 is linked to carcinoma.