This study is implemented in association with the study "J-TAIL-2" ; prospective multicenter observational study of atezolizumab in patients with unresectable, locally advanced or metastatic non-small cell lung cancer, UMIN study ID: UMIN000041263, to evaluate biomarkers for selection of appropriate patients in treatment with atezolizumab combination therapy.

Inclusion Criteria:

Inclusion/exclusion criteria of J-TAIL-2 study is to be applied.

<non-small cell lung cancer cohort>

1. Patients 20 years of age or older at the time of signed consent.
2. Patients with unresectable, advanced and recurrent non-small cell lung cancer.
3. Patients who are scheduled to start atezolizumab combination therapy in clinical practice, based on the atezolizumab package insert and the Optimal Clinical Use Guideline.
4. Patients who signed informed consent form before enrolling the study. The consent from a legally acceptable representative is required for the patients with uncertain capacity of judgments.

<extensive disease small cell lung cancer cohort>

1. Patients 20 years of age or older at the time of signed consent.
2. Patients with extensive disease small cell lung cancer.
3. Patients who are scheduled to start atezolizumab combination therapy in clinical practice, based on the atezolizumab package insert and the Optimal Clinical Use Guideline.
4. Patients who signed informed consent form before enrolling the study. The consent from a legally acceptable representative is required for the patients with uncertain capacity of judgments. However, the samples of dead cases can be used for the analysis of immune microenvironment of small cell lung cancer by disclosing information on this study.

Exclusion Criteria:

<non-small cell lung cancer cohort>

1. Patients who are unsuitable for enrolment into the study by the investigator's judgment.

<extensive disease small cell lung cancer cohort>

1. Patients who are unsuitable for enrolment into the study by the investigator's judgment.

Patients who are planning to provide atezolizumab combination therapy as the most appropriate medical care for patients and who meet the Eligibility criteria at registration.

All IPD that underlie results in a publication.

After the end of the study