EGFR and cholangiocarcinoma: To examine whether this is the case for another donor, HD11 NK cells were subjected to the same assay systems, revealing that HuCCT1, MzChA2, and TGBC2TKB were highly sensitive to the direct cytotoxicity by HD11 NK cells, and the add-on effect of anti-EGFR mAb was observed in all CCA cell lines to different degrees (Figure 4B).