a. 2D sequence of pRNA 3WJ domain composed of three RNA oligomers (a, b, c), folic acid (FA) and near-infrared fluorescent dye Alexa647 (left); 3D model and AFM images of pRNA 3WJ motif harboring monomeric pRNA as functional modules. b. The most common sites of CRC metastasis—liver, lung and lymph nodes. The FA-conjugated pRNA (FA-pRNA) nanoparticle targets FRα positive tumors upon systemic administration. c. CRC liver, lung and lymph node experimental metastasis modes (Green: metastatic tumors)