TWIST1 and head and neck squamous cell carcinoma: To further examine the interaction between endogenous CK2α and Twist protein in SCCHN cells, the FaDu cell line was chosen because it expresses a high basal level of CK2 protein; HN31 SCCHN cells that stably express Myc-tagged Twist (HN31 Myc-Twist SCCHN cells) were established for immunoprecipitation purposes because of the poor performance of the commercially available Twist antibodies.