CEACAM5 and neoplasm: There were no significant differences in clinical factors (including sex, smoking history, and CEA), the mutation rate of Del-19 or L858R, and tumor location in each EGFR mutant subtype group (all P > 0.05), while there were significant differences in age between the two EGFR mutant subtype groups (Del-19 vs. wild type, Del-19 vs. L858R) (Supplementary Tables S1–S3).