GFAP and neoplasm: Circulating tumor cells (CTCs) (4′,6-diamidino-2-phenylindole (DAPI) + glial fibrillary acidic protein (GFAP) + epidermal growth factor receptor (EGFR) + CD45−CD66b−) zero-converted after therapy (16 CTCs in 7.5 ml blood detected on day −9 versus zero CTCs on day +190; Extended Data Fig. 1).