Distribution of mutation type according to exposure to overall passive smoking for EGFR and KRAS
| Never exposed | Ever exposed | p-value | |
| EGFR | |||
| Mutation in exon 18 | 0 (0) | 3 (4) | NC |
| Mutation in exon 19 | 27 (60) | 49 (60) | |
| Mutation in exon 20 | 2 (4) | 3 (4) | |
| Mutation in exon 21 | 14 (31) | 24 (30) | |
| Double mutation in EGFR gene | 2 (4) | 2 (2) | |
| Missing | 1 | ||
| KRAS | |||
| Transition# | 2 (40) | 2 (18) | 0.547 |
| Transversion¶ | 3 (60) | 9 (82) | |
| Missing | 1 | 1 |
Data are presented as n (%) or n, unless otherwise stated. EGFR: epidermal growth factor receptor; KRAS: Kirsten rat sarcoma viral oncogene homologue; NC: not computable. #: G13D, G12G or G12D; ¶: G12V, G12R or G12A.