This is a single-center, open-label, controlled mechanistic study before-and-after allergen instillation study that uses each subject as his/her own control. Reliability of study measurements of expression is accomplished by comparing repeated measurements. Additional controls are provided by measuring the expression of markers known to have stable expression, including cell structural proteins and chemokine markers that the investigators know are induced in this experimental paradigm from our previous studies. This is an investigational study. Subjects will receive an investigational product, either Standardized Cat Allergen Extract or Standardized Dust Mite Allergen (Dermatophagoides farinae or D. pteronyssinus). No subject will be given a placebo. There are 2 cohorts, allergic asthmatics (AA) and healthy controls (HC). The main comparisons will be measurement of primary and secondary outcome measures in: (1) diluent versus allergen-challenged segments of the lung in each asthmatic subject and (2) comparison of these responses in allergic asthmatics (AA) and healthy controls (HC).