JAG2 and Langerhans cell histiocytosis: Interestingly, active Notch signaling can be detected in LCH lesions, and the Notch agonist Jagged-2 (Jag2) was described to promote the differentiation of CD14+ monocytes into CD1a+CD207+ LCs that express a gene-signature similar to that of LCH cells (45, 46).