Interestingly, the ctDNA sensitivity in our study was substantially lower than that observed in the HERACLES trial, where 47 of 48 samples (97.9%) from 29 patients with HER2-positive CRC had ERBB2 amplification detectable on the same Guardant360 platform.40 Furthermore, the adjusted copy number of 25.82 copies predicted who would benefit from trastuzumab in combination with lapatinib. The gene discussed is ERBB2; the disease is colorectal carcinoma.