Tumor–to–contralateral site ratios were significantly higher (P < 0.05, Mann–Whitney test) for HER2-positive than for HER2-negative tumors at 2 and 4 h after injection with 1,000 and 2,000 μg, but the difference was not significant 6 h after injection (Fig. 5). The gene discussed is ERBB2; the disease is neoplasm.