According to the NCI website anti-ACTR/4-1BB/CD3zeta-viral vector-transduced autologous T lymphocytes ACTR087 are autologous T lymphocytes that are genetically modified and transfected with a viral vector expressing the ACTR gene, a proprietary gene encoding for an antibody-coupled T cell receptor (ATCR), with potential antineoplastic activity.

Link to National Cancer Institute