We are interested in elucidating mechanisms by which a mutation or combination of mutations affect broader network within and between cells during development. Our current model is DiGeorge/velocardiofacial/del22q11 syndrome (OMIM: 188400 and 192430), a contiguous gene syndrome in approximately 1 in 4000 live births. The common manifestations of this syndrome include cardiovascular defects, aplasia or hypoplasia of the thymus and parathyroid glands, and craniofacial anomalies. Urogenital defects, learning disabilities, and other psychiatric disorders are also common. Two 22q11 genes, TBX1 and CRKL, have been implicated in this syndrome. While they show a strong dosage-sensitive interaction in mouse models, they encode different classes of proteins. Tbx1 is a T-box transcription factor, while CRKL is an adapter protein presumably down stream of tyrosine kinases. To date, few direct links have been known between the signaling pathways in which they are involved. Using multitudes of techniques, we aim to find missing pieces to establish their functional links.