This study will collect blood and sputum (phlegm) samples from subjects with asthma, smokers and normal healthy subjects, to compare the biological markers of disease and inflammation.

Inclusion Criteria (healthy subjects):

• Male or female, between 18 and 55 years of age, inclusive.
• no clinically significant abnormalities.
• able to produce an adequate induced sputum sample.
• no history of chronic respiratory disease including asthma.
• no history of allergic symptoms e.g., allergic rhinitis, eczema.
• No other acute illness in the 6 weeks prior to Visit 1.

Additional Inclusion Criterion for Healthy Smoking Subjects

• Be a smoker for >/= 1 year.

Additional Inclusion Criteria (Persistent Asthmatic Subjects):

• No contraindications to the procedures in this study.
• Symptoms compatible with asthma for at least 6 months prior to screening
• Pre-bronchodilator FEV1 >/=50% predicted at Visit 1.
• clinically stable asthma for at least 6 weeks prior to Visit 1.
• No acute illness including asthma exacerbation requiring augmentation of therapy in the 6 weeks prior to Visit 1.
• on current asthma controller therapy for >/= 6 weeks prior to Visit 1.

Additional Inclusion for Steroid Naïve Asthmatics (smoking or non-smoking)

• Must not have received a regular course of inhaled or oral corticosteroids for at least 3 months prior to Visit 1.

Additional Inclusion for Smoking Asthmatics

• Be a smoker for >/= 1 year prior to Visit 1.

Exclusion Criteria (healthy):

• History of any clinically significant medical illness or medical disorders.
• Diagnosis of chronic obstructive pulmonary disease (COPD), cystic fibrosis, or other significant respiratory disorder including significant occupational or environmental exposures with ongoing respiratory symptoms.
• bronchodilator response of >/=12% and at least 200 mL from baseline or an FEV1 value <85% of predicted value at Visit 1.
• positive urine pregnancy screening result.
• recent history (within previous 6 months) of alcohol or drug abuse.
• Positive urine toxicology screen for substances of abuse
• positive serology test for HIV antibodies, hepatitis B surface antigen (HBsAg), or hepatitis C virus antibody (anti-HCV) at Visit 1.
• Received an experimental antibody or biologic therapy within the 6 months prior to Visit 1, or received any other experimental therapy or new investigational agent within 60 days of Visit 1.
• Is an employee or family member of the investigator, study centre or Sponsor.
• Any condition that, in the opinion of the investigator, would complicate or compromise the study, or the well-being of the subject.
• Use of any antioxidants within 1 week of Visit 1 and throughout the study period.
• known allergies, hypersensitivity, or intolerance to short acting β-agonists (SABA).

Additional Exclusion Criterion for Healthy Non-smoking Subjects

• subject is a smoker (regular or irregular), or has smoked or used nicotine-containing products within the 6 months prior to Visit 1.

Additional Exclusion Criteria (Persistent Asthma Subjects):

• Diagnosis of allergic bronchopulmonary aspergillosis (ABPA), allergic bronchopulmonary mycosis (ABPM), or occupational asthma.
• Diagnosis of COPD, cystic fibrosis, or other significant respiratory disorder including significant occupational or environmental exposures with ongoing respiratory symptoms.
• Use of theophylline, N-acetyl cysteine, or any other anti-oxidants within 1 week of Visit 1 and throughout the study period.
• positive test for tuberculosis at Visit 1.

Additional Exclusion Criterion for Non-smoking Asthmatic Subjects

• subject is a smoker (regular or irregular), or has smoked or used nicotine-containing products within the 6 months prior to Visit 1.

Subjects will be selected by advertisements from the general population and primary care.