GPC1 and esophageal squamous cell carcinoma: We then tested the affinity of the chicken/mouse chimeric anti-GPC1 mAb in two native ESCC cell lines (TE8 and TE14), one GPC1-negative lung squamous carcinoma cell line (LK2) and an LK2-derived cell line (LK2-hGPC1) by flow cytometry.