Using flow cytometric analysis, Latchman et al. (2001) showed that the IgV region of mouse Pdl2, like Pdl1, binds to human PDCD1 but not to CTLA4, CD28 , or ICOS. Stimulation of mouse T cells with anti-CD3 and Pdl2 or Pdl1 resulted in inhibition of proliferation and cytokine production, and Pdl2 could inhibit T-cell receptor -CD28 signals at low antigen concentrations. Latchman et al. (2001) proposed that blocking of the PDL-PDCD1 pathway may enhance antitumor immunity, whereas stimulating this pathway may help downregulate graft rejection and autoimmune and allergic reactions.

Latchman et al. (2001) mapped the PDL2 gene to chromosome 9p24.2, in close proximity to the PDL1 gene. Tseng et al. (2001) mapped the mouse Pdl2 gene to chromosome 19C2-C3.