CD53 and neoplasm: To determine whether T cells expressing CIRs on their surfaces could serve as a platform for screening and isolating binders to tumor specific cell surface antigen, JurkatαCEA-CIR-EGFP cells and CIR-negative non-transduced Jurkat cells (Fig. 6) or CIR-positive transfected Jurkat cells (JurkatαNIP-CIR) (Fig. 7) were mixed at decreasing concentrations of the former, with a total number of 3×107 and incubated overnight with confluent monolayers of HeLaCEA cells, and the sensitivity of the isolation and enrichment process evaluated.