ENPP3 and asthma: Because CD203c has been identified as a basophil activation marker [30], [31] and because recent studies have revealed that the expression of CD203c on basophils is useful in the diagnosis of food allergies and asthma [31], [32], the CD203c promoter was introduced in place of the alb promoter of the original TRECK cassette to facilitate the exclusive expression of hDTR on basophils (Fig. 1A).