ERBB2 and metastatic neoplasm: However, the HS values of KRAS, HER2, and PIK3CA mutations were significantly higher in metastatic tumors (KRAS: median 1.61, IQR 1.15–2.53, n = 13; HER2: median 2.45, IQR 1.13–2.81, n = 5; PIK3CA: median 1.32, IQR 0.76–1.96, n = 5) than in primary tumors (KRAS: median 0.91, IQR 0.47–1.50, n = 41, P = 0.002; Fig. 4B; HER2: median 0.75, IQR 0.44–1.30, n = 16, P = 0.021; Fig. 4C; PIK3CA: median 0.32, IQR 0.15–1.08, n = 13, P = 0.044; Fig. 4E).