PTPA and asthma: Here, we showed that DPP4 deficiency results in a reduction of Mid1, a key protein that binds to and regulates the function of microtubules.[20] Mid1 interacts with the α4 regulatory subunit of the PP2A and mediates the ubiquitin‐dependent degradation of catalytic subunit PP2Ac.[20] Additionally, Mid1 is involved in allergen‐induced asthma by inhibiting PP2A in bronchial epithelial cells.[17] However, its role in vascular disease has yet to be elucidated.