The PathHunter PD-L2 Ligand cell line is a stable, engineered cell line designed for use with PD-1 Checkpoint Signaling Cell Lines. When co-cultured, the PD-L2 expressed in this cell line will induce activity of PD-1 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 PD-L2 cell surface ligand. When co-cultured with the PD-1 Checkpoint Signaling Cell Lines, the PD-L2 ligand binds to the checkpoint receptor, inducing receptor activity. This receptor activity leads to recruitment of the relevant SH2 domain protein to the checkpoint receptor inside the receptor cell line and production of EFC signal. This stable modified cell line is provided as two vials of cryopreserved cells.