Similarly, the increase of male sex hormone is beneficial in asthma, as the protective effect from puberty to adulthood reverses in old age is believed due to the reduced level of androgen [80], and androgen supplementation induces bronchodilatation [146], decreases Th17 (IL17) expression, and reduces the neutrophilic asthma prevalence and exacerbations. Here, IL17A is linked to asthma.