tokens: In agreement with the patterns seen with trypsinization , BT . siLuc and BT . siMUC1 respond similarly to all treatments ( data not shown ) , while 468 . siMUC1 die more readily than 468 . siLuc in response to trypsin , G418 , hydrogen peroxide , or celecoxib , a chemotherapeutic that targets the cyclooxygenase - 2 ( COX - 2 ) pathway ( Figure 4c ) ; these data were confirmed with two independent siRNA constructs ( data not shown ) .