EGFR and non-small cell lung carcinoma: For example, Amornwichet et al. reported that the RBE of carbon ions in nine epidermal growth factor receptor (EGFR)-wild-type non-small cell lung carcinoma (NSCLC) cell lines was 2.6 ± 0.3 at the center of the 6-cm-wide spread-out Bragg peak (SOBP) [11], whereas Kagawa et al. reported that the RBE in human salivary gland (HSG) cells, the cell line used as the reference in the clinical CIRT beam set-up, was 1.8 at the center of the same 6-cm SOBP [5].