ROR1 and lung adenocarcinoma: To examine expression of ROR1 in lung adenocarcinoma, we first chose Erlotinib-sensitive cell line PC-9, Erlotinib-partially sensitive cell line NCI-H358, and Erlotinib-resistant cell lines XLA-07, A549, NCI-H1975, and MSTO-211H (Table 1), to determine ROR1 expression by flow cytometry (Fig 1A).