However, we previously revealed that, in an evaluation of emerging genomic alterations in circulating tumor DNA (ctDNA) after anti-EGFR therapy in 55 patients with mCRC that was initially wild-type RAS and non-HER2-amplified, HER2 amplifications were newly identified after therapy only in three patients (5.5%), with a low median CN (adjusted value = 4.0), suggesting that it could not be targeted by anti-HER2 treatment [28]. Here, ERBB2 is linked to neoplasm.