The T-SMPDC, DOTA-PEG3-TZ(PEG4-Octr)-PEG2-Trz-PEG3-Val-Cit-pABOC-FTY720, is built upon a 1,3,5-triazine core (TZ) to present three functionalities: (1) a chelating moiety (DOTA) for PET imaging when labeled with 68Ga (t1/2 = 68 min) or other relevant radiometals; (2) an octreotide (Octr) that targets somatostatin receptor 2 (SSTR2), which is overexpressed in the innervated tumor microenvironment (TME) [17,22,23,24]; and (3) FTY720 coupled with a cathepsin-B-cleavable linker comprising a valine–citrulline (Val-Cit) motif and a p-amino-benzyloxycarbonyl (pABOC) moiety. This evidence concerns the gene SSTR2 and neoplasm.