The amplification of MYC, CCNE1, and ERBB2 was more frequently detected in CSF than in tumor tissue samples, with detection rates being 46.7% (7/15) vs 26.7% (4/15), 53.3% (8/15) vs 13.3% (2/15), and 26.7% (4/15) vs 13.3% (2/15), respectively (Fig. 1A). Here, ERBB2 is linked to neoplasm.