The PathHunter HVEM Ligand cell line is a stable, engineered cell line designed for use with BTLA Checkpoint Signaling Cell Lines. When co-cultured, the HVEM expressed in this cell line will induce activity of BTLA receptors, which may be assayed through SH2 domain protein recruitment. This product is a companion product designed to work with Immunoglobulin Superfamily Checkpoint Assays. The cell line included overexpresses HVEM cell surface ligand. When co-cultured with the BTLA Checkpoint Signaling Cell Line, the HVEM ligand binds to the checkpoint receptor, inducing receptor activity. This receptor activity leads to stabilization of ED-tagged NIK, allowing detection of EFC signal when treated with exogenous EA. This stable modified cell line is provided as two vials of cryopreserved cells.