- Subsets of the major tyrosine phosphorylation sites in Crk-associated substrate (CAS) are sufficient to promote cell migration. Nah-Young Shin, Rebecca S. Dise, Jens Schneider-Mergener, Marylyn D. Ritchie, Dawn M. Kilkenny, Steven K. Hanks, 279, 37, 38331-38337, The of biological chemistry, 2004 Sep 10, PMID: 15247284,