NUCLEOLIN and neoplasm: Additionally, the aforementioned F3-peptide-targeted pH-sensitive liposomes containing doxorubicin (Dox; used as a model drug) efficiently decreased both the tumor viable rim area and microvascular density, limiting tumor invasion in nucleolin-overexpressing MDA-MB-435S-derived tumors implanted in the mammary fat pad of female Balb/c nude mice [18].