MT2A and asthma: Secondary outcomes will include the following: (1) the Asthma Quality of Life Questionnaire, Asthma Control Test, and Asthma Long-term Follow-up Scale; (2) levels of Metallothionein-2 and Transgelin-2 in blood and urine; and (3) levels of IL-5, IL-13, IL-23, IL-25, and thymic stromal lymphopoietin in blood.