In SKOV3-bearing mice pretargeted with ZHER2:342-SR-HP1, tumor uptake of 177Lu-HP2 was about twice higher than 68Ga-HP2 (12 ± 3 vs. 6.3 ± 1.5% ID/g, p = 0.00006, one-way ANOVA test), while in DU145 tumors with low Her2 expression no difference in uptake was observed. The gene discussed is ERBB2; the disease is neoplasm.