We selected a piperidine-based (Pip) linker as our cationic hydrophilic linker, as previous studies showed that the use of the Pip linker in a derivative of the α-melanocyte-stimulating hormone to target the melanocortin-1 receptor resulted in not only improved tumor uptake, but also higher tumor-to-organ ratios [29]. The gene discussed is MC1R; the disease is neoplasm.