Both the RGD4C-AAVP-TNF and RGDC4C-AAVP-HSVtk constructs achieved the intended cytotoxic and theranostic effects, respectively, demonstrating the potential for using M13 φ as a theranostic for the treatment of human gliomas and potentially other brain tumors (Staquicini et al., 2020). Here, TNF is linked to glioma.