Being abundant in the cerebellum and retina [17], PLCß4 contributes to the development of the first and second pharyngeal arches in the embryo, and germline PLCB4 mutations occur in most patients with auriculocondylar syndrome, a rare craniofacial malformation manifesting mandibular deformity and characteristic “question-mark” ears [18]. Here, PLCB4 is linked to auriculocondylar syndrome.