Clinical endotypes of airway diseases are undermining successful treatment of allergic diseases. Novel biomarkers were identified and are summarized, but really critical is the future strategy to combine several markers to generate powerful prediction algorithms. These should be strong enough to allow conclusions for individual patients. Biomarkers beyond the type-2 group may allow distinction of patients even in the temporary absence of triggering factors such as allergens. But also noninvasive sampling methods taking advantage of nasal secretions are promising and are summarized in this chapter.