Here, the modular nature and small size of the nanobody could be advantageous: bi-specific nanobodies targeting CD39 on cancer cells and cancer-specific antigens e.g. epidermal growth factor receptor (EGFR) could establish an ATP focus within solid tumors, as a small dimeric, bi-specific nanobody construct of ~30 kDa is predicted to penetrate deep into solid tumors. The gene discussed is EGFR; the disease is cancer.