Prostate membrane specific antigen (PSMA-1) peptide was used in a study by Luo et al. (71) on ultrasmall AuNPs (3.0 ± 0.7) nm or PSMA-1-AuNPs (5 nm) in mice bearing prostate cancers (PC3pip and PC3flu tumors). The gene discussed is FOLH1; the disease is prostate cancer.