SMAD4 and neuroblastoma: • Poldip2: Promotes retinal fibrosis via TGF-β1/Smad • PCK2: Enhances TGF-β/Smad3 in TNBC • aPKCs: Upregulate TGF-β via Smad2/3 in NB • Smad4: Biomarker for JPS