The same NT4 peptide has also been conjugated to different tracers or drugs and tested as a tumour-targeting agent for cancer cell imaging and therapy, demonstrating its potential as a cancer theranostic agent (Falciani et al., 2007; Falciani et al., 2010b; Falciani et al., 2011; Brunetti et al., 2018; Brunetti et al., 2015b). This evidence concerns the gene NTF4 and cancer.