IL13 and asthma: When available, Fractional exhaled Nitric Oxide (FeNO) levels are correlated with Interleukin-13 (IL-13) levels, and both are indicators of type 2 inflammation in the airways.351, 352 Objective tools such as the Asthma Control Test (ACT) and the Asthma Quality of Life Questionnaire (AQLQ) or mini-AQLQ are used to assess patients’ quality of life, as well as periodic measurements of Peak Expiratory Flow.185, 351, 352 Asthma is a very important component of AERD and should be diagnosed and treated appropriately by specialists.