The purpose of this study is to learn more about asthma in people who are not well-controlled with current asthma medication (refractory asthma). The investigators will compare data from refractory asthmatic patients here at National Jewish Health to mild asthmatics subjects and to people without asthma. Study experiments involve looking at samples from all 3 groups and comparing them at a molecular level. These laboratory experiments may help identify subtypes of refractory asthmatics that require different treatments.

Inclusion Criteria:

• Able to receive Informed Consent
• At least 18 years of age
• ICS < 880 mcg (FP equivalents)
• PC20<=16 mg/mL
• No more than 1 oral steroid bursts in previous 12 months
• Less that 3 urgent care visit in previous 12 months
• No deterioration with <=25% decrease in steroids
• No near fatal asthma event

Exclusion Criteria:

• Pregnancy
• Current smoker, smoking within the past year or pack/year history >10 years
• Respiratory infection within past 6 weeks
• Antibiotics within the past 6 weeks
• Active lung disease other than asthma
• Cancer within past 5 years (excluding basal cell skin cancer)
• Active or chronic infection
• Hematological or autoimmune disease
• Unable to safely undergo bronchoscopy as determined by doctor or study doctor

We are looking for mild non-smoking asthmatic adults who are well-controlled with their asthma therapy (non-refractory asthmatics).