IL13RA1 and asthma: The CAS concept has also been found to be the case in a human cohort study showing that CAS in the context of AD, but not in the non-AD context, increases the risk of asthma as part of the atopic march.(64–66) Consistently, type 2 inflammation increased the number of IL-13R+ PBDCs in humans and mice (Fig.4c & Fig.8b).