CRK and cancer: Second, it may serve as a therapeutic target in some cancers like glioblastoma and breast cancer using RNAitechnology.16 It has been found that siRNA-mediated gene silencing of Crk significantly reduced migration and invasive behavior of tumor cells in both glioblastoma16,30 and breast cancer.31 However, there seems to be no study on the status of CrkII expression in malignant and benign tumors of salivary glands.