Despite upregulation of 2B4 on T cells with increasing myeloma burden, which has also been observed on CD8 and CD4 T cells in a mouse pancreatic cancer model [60], blockade of PD-L1 plus the ligand for 2B4, CD48, did not provide any additional benefits over PD-L1 blockade alone. This evidence concerns the gene CD4 and familial pancreatic carcinoma.