CD19 and neoplasm: Since one of the primary mechanisms of GZMB activation is to directly activate pro-caspase 3 in tumor cells, we confirmed via western blotting that the expression of pro-caspase 3 was not different between NALM6 and NALM6-PI9 and SkOV3-CD19 and SkOV3-CD19-PI9 (Fig. S3).