Inclusion Criteria:

- Advanced/recurrence NSCLC patients who have had one or more chemotherapy regimens.

- Patients who are to be treated with gefitinib or chemotherapy

- Cohort: All advanced/recurrence NSCLC patients participating in this post-marketing
clinical study

Exclusion Criteria:

- Patients judged by the investigator(s) to have ILD (provisional cases) among those
registered in the cohort OR Randomly selected patients without ILD (controls) for
each provisional case

- Case-control study: Patients enrolled in the case-control study; all consenting
patients with ILD as cases and approximately 4 times as many consenting patients
without ILD as controls randomly selected from the cohort