To determine the mechanisms underlying the progression from AD to asthma, we first generated animals that lacked Notch signaling in a portion of their skin surfaces by embryonic removal of RBP-j from keratinocytes using the Msx2-Cre transgene (Msx2-Cre/+;RBP-jflox/flox or RBP-jCKO). The gene discussed is MSX2; the disease is asthma.