RNPC3 and neoplasm: The HA/CP/Ad‐SS‐GD/RNP showed excellent tumor targeting and antitumor effects in terms of a reduction in tumor volume, more terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells in the tumor, a reduced percentage of Ki67‐positive cells, and inhibition of tumor metastasis.[172] All trans‐retinoic acid is a small molecule that binds to interphotoreceptor retinoid‐binding protein of the retinal pigment epithelium (RPE) and photoreceptor outer segments and is therefore used as an active targeting moiety of delivery in retinal cells in vitro and in vivo.