Moreover, to investigate the in vitro effectiveness of the CD1a x CD3ε in the context of active T-ALL disease, a cytotoxic assay at low E:T ratio (from 1:1 to 5:1) was performed by co-culturing PBMCs with HPB-ALL cell line in the presence of CD1a x CD3ε. The gene discussed is CD1A; the disease is acute lymphoblastic leukemia.