The cell binding of the MSLN/CD3 bsAb was tested on MSLN-negative cell line A431, MSLN-overexpressing A431 cells (named H9), and MSLN-positive pancreatic cancer cell lines KLM-1 and T3M4, as well as different subsets of T cells (PBMC、NKT、γδT). This evidence concerns the gene MSLN and familial pancreatic carcinoma.